 |
Matronics Email Lists
Web Forum Interface to the Matronics Email Lists
|
| View previous topic :: View next topic |
| Author |
Message |
w7ikt(at)fly-web.us
Guest
|
 Posted: Wed Sep 12, 2012 5:27 am Post subject: [Pulsar-Aviators] 912 Hiccup |
 |
|
Bob,
This has some similarities to my accident. I believe the electric fuel pump blocked fuel flow in my plane. When the fuel pump was removed I could not blow thru it in either direction, should have been able to in the direction of flow. After shipping the fuel pump to the NTSB it operated normally. Do you have a bypass and check valve around the electric fuel pump?
God Bless
Bob Heiser W7IKT
On 9/10/2012 6:23 PM, Bob Hartunian wrote:
[quote]
Flew out locally for bkfst on Sunday, past mountains to flatlands and landed and all was fine. Got back into plane 45 min later and started up fine. Did normal runup and had 5 gal in left tank, full right tank, running off left, all was fine.
Took off normally and did another normal left crosswind turn toward home and mountains. All indications normal including fuel pressure. Climbing at 500 fpm, 100 mph, engine around 5100 rpm, when suddenly engine rpm drops to almost idle. No shaking or vibes. Immediately kicked on electric fuel pump but saw no indications for low fuel pressure, and engine came back normally. I don’t think the fuel pump really did anything as engine just regained rpm and flew perfectly all the way home for another 20 min. out over desert just in case.
I pulled cowl and checked things visually but no obvious problems. Don’t have a good explanation for why rpm dropped.
Bob H
__,_._,___
[b]
| | - The Matronics Pulsar-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Pulsar-List |
|
|
|
| Back to top |
|
 |
barrynorman(at)comcast.ne
Guest
|
| Posted: Wed Sep 12, 2012 6:18 am Post subject: [Pulsar-Aviators] 912 Hiccup |
|
|
I had an event this summer that was similiar but I don't think it had anything to do with the fuel pump. It was a fairly warm day and I had taken my son up for a ride in the Pulsar III and returned after a 30 minute flight where everything was perfectly normal. I shut the plane down for a few minutes while we loaded another passenger and had a very difficult time restarting the plane. This was not anything new in this situation as I think the fuel starts to boil in the bowls making it difficult to start and get fresh fuel in due to the pressure in the bowls. I finally got it started and it ran rough for a few minutes but cleared up. I taxied to the runway and as I fed in power for takeoff, the RPM dropped and the engine quit. The plane refused to restart so I brought it back to the hanger. I came back the next day and the plane started right up and ran fine. This is a pattern I've noticed on my plane that appears to be vapor lock on warm days. Once those carb bowls get heat soaked from sitting, the problem shows up.
Barry
From: "Bob Heiser" <w7ikt(at)fly-web.us>
To: pulsar-list(at)matronics.com
Sent: Wednesday, September 12, 2012 9:27:00 AM
Subject: Re: [Pulsar-Aviators] 912 Hiccup
Bob,
This has some similarities to my accident. I believe the electric fuel pump blocked fuel flow in my plane. When the fuel pump was removed I could not blow thru it in either direction, should have been able to in the direction of flow. After shipping the fuel pump to the NTSB it operated normally. Do you have a bypass and check valve around the electric fuel pump?
God Bless
Bob Heiser W7IKT
On 9/10/2012 6:23 PM, Bob Hartunian wrote:
[quote]
Flew out locally for bkfst on Sunday, past mountains to flatlands and landed and all was fine. Got back into plane 45 min later and started up fine. Did normal runup and had 5 gal in left tank, full right tank, running off left, all was fine.
Took off normally and did another normal left crosswind turn toward home and mountains. All indications normal including fuel pressure. Climbing at 500 fpm, 100 mph, engine around 5100 rpm, when suddenly engine rpm drops to almost idle. No shaking or vibes. Immediately kicked on electric fuel pump but saw no indications for low fuel pressure, and engine came back normally. I don’t think the fuel pump really did anything as engine just regained rpm and flew perfectly all the way home for another 20 min. out over desert just in case.
I pulled cowl and checked things visually but no obvious problems. Don’t have a good explanation for why rpm dropped.
Bob H
__,_._,___
arget=_blank>http://www.matronics.com/Navigator?Pulsar-List
p://forums.matronics.com
blank>http://www.matronics.com/contribution
[b]
| | - The Matronics Pulsar-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Pulsar-List |
|
|
|
| Back to top |
|
|
bernard.wilder2(at)gmail.
Guest
|
| Posted: Wed Sep 12, 2012 7:04 am Post subject: [Pulsar-Aviators] 912 Hiccup |
|
|
Bob,
You may remember that my initial theory was that the problem was with the electric fuel pump.
Barry,
Is your electric fuel pump mounted on a 45 degree angle ? ? ? Mine specified that it should be,
Do you have a jetted fuel line going from the fuel line between the engine fuel pump and the carbs back to your fuel cells ? ? ? Rotax standard instalation instructions specify that there be one.
Even with this bleed back path for hot fuel, and vapor formed in the fuel line when the fuel cooks off and turning on the electric fuel pump,, on a hot day when I forget to open the hatch on the top of my cowl it is common for the engine to falter four to five minutes after re-start. On such days I turn on my electric fuel pump run my engine long enough to be past the time that the engine will run on the fuel left over in the carb bowls.
Bernie Wilder
On Wed, Sep 12, 2012 at 9:27 AM, Bob Heiser <w7ikt(at)fly-web.us (w7ikt(at)fly-web.us)> wrote:
[quote] Bob,
This has some similarities to my accident. I believe the electric fuel pump blocked fuel flow in my plane. When the fuel pump was removed I could not blow thru it in either direction, should have been able to in the direction of flow. After shipping the fuel pump to the NTSB it operated normally. Do you have a bypass and check valve around the electric fuel pump?
God Bless
Bob Heiser W7IKT
On 9/10/2012 6:23 PM, Bob Hartunian wrote:
| Quote: |
Flew out locally for bkfst on Sunday, past mountains to flatlands and landed and all was fine. Got back into plane 45 min later and started up fine. Did normal runup and had 5 gal in left tank, full right tank, running off left, all was fine.
Took off normally and did another normal left crosswind turn toward home and mountains. All indications normal including fuel pressure. Climbing at 500 fpm, 100 mph, engine around 5100 rpm, when suddenly engine rpm drops to almost idle. No shaking or vibes. Immediately kicked on electric fuel pump but saw no indications for low fuel pressure, and engine came back normally. I don’t think the fuel pump really did anything as engine just regained rpm and flew perfectly all the way home for another 20 min. out over desert just in case.
I pulled cowl and checked things visually but no obvious problems. Don’t have a good explanation for why rpm dropped.
Bob H
__,_._,___
arget="_blank">http://www.matronics.com/Navigator?Pulsar-List
ttp://forums.matronics.com
_blank">http://www.matronics.com/contribution
|
[b]
| | - The Matronics Pulsar-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Pulsar-List |
|
|
|
| Back to top |
|
|
barrynorman(at)comcast.ne
Guest
|
| Posted: Wed Sep 12, 2012 8:00 am Post subject: [Pulsar-Aviators] 912 Hiccup |
|
|
My manuals never mentioned mounting the fuel pump at 45 degrees or routing fuel back to the tank via a return line. As a matter of fact, there were no provisions in the end plates for a fuel return or a selector switch for feeding back to the appropriate tank. There wasn't any information on a bypass for the electric pump either.
Barry.
From: "Bernard Wilder" <bernard.wilder2(at)gmail.com>
To: pulsar-list(at)matronics.com
Sent: Wednesday, September 12, 2012 11:02:26 AM
Subject: Re: Re: [Pulsar-Aviators] 912 Hiccup
Bob,
You may remember that my initial theory was that the problem was with the electric fuel pump.
Barry,
Is your electric fuel pump mounted on a 45 degree angle ? ? ? Mine specified that it should be,
Do you have a jetted fuel line going from the fuel line between the engine fuel pump and the carbs back to your fuel cells ? ? ? Rotax standard instalation instructions specify that there be one.
Even with this bleed back path for hot fuel, and vapor formed in the fuel line when the fuel cooks off and turning on the electric fuel pump,, on a hot day when I forget to open the hatch on the top of my cowl it is common for the engine to falter four to five minutes after re-start. On such days I turn on my electric fuel pump run my engine long enough to be past the time that the engine will run on the fuel left over in the carb bowls.
Bernie Wilder
On Wed, Sep 12, 2012 at 9:27 AM, Bob Heiser <w7ikt(at)fly-web.us (w7ikt(at)fly-web.us)> wrote:
[quote] Bob,
This has some similarities to my accident. I believe the electric fuel pump blocked fuel flow in my plane. When the fuel pump was removed I could not blow thru it in either direction, should have been able to in the direction of flow. After shipping the fuel pump to the NTSB it operated normally. Do you have a bypass and check valve around the electric fuel pump?
God Bless
Bob Heiser W7IKT
On 9/10/2012 6:23 PM, Bob Hartunian wrote:
| Quote: |
Flew out locally for bkfst on Sunday, past mountains to flatlands and landed and all was fine. Got back into plane 45 min later and started up fine. Did normal runup and had 5 gal in left tank, full right tank, running off left, all was fine.
Took off normally and did another normal left crosswind turn toward home and mountains. All indications normal including fuel pressure. Climbing at 500 fpm, 100 mph, engine around 5100 rpm, when suddenly engine rpm drops to almost idle. No shaking or vibes. Immediately kicked on electric fuel pump but saw no indications for low fuel pressure, and engine came back normally. I don’t think the fuel pump really did anything as engine just regained rpm and flew perfectly all the way home for another 20 min. out over desert just in case.
I pulled cowl and checked things visually but no obvious problems. Don’t have a good explanation for why rpm dropped.
Bob H
__,_._,___
arget="_blank">http://www.matronics.com/Navigator?Pulsar-List
ttp://forums.matronics.com
_blank">http://www.matronics.com/contribution
|
arget=_blank>http://www.matronics.com/Navigator?Pulsar-List
p://forums.matronics.com
blank>http://www.matronics.com/contribution
[b]
| | - The Matronics Pulsar-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Pulsar-List |
|
|
|
| Back to top |
|
|
barrynorman(at)comcast.ne
Guest
|
| Posted: Wed Sep 12, 2012 8:36 am Post subject: [Pulsar-Aviators] 912 Hiccup |
|
|
I found a detailed installation guide on the Internet on the facet pump and they do recommend mounting the pump at a 45 degree angle to allow buildup of vapors to pass through the pump easily. Unfortunately the location of the pump doesn't allow for it and I don't think a buildup of vapors exists near the pump because it doesn't get hot there inside the cabin. In fact, when I'm having a hard start problem after it's heat soaked, the only way I can get it started is when I turn on the electric pump, so I know it's functioning properly. What works for me is to take the upper engine cowl off during short stops for refueling or whatever and that stops the heat soaking and vapor lock problems.
From: barrynorman(at)comcast.net
To: pulsar-list(at)matronics.com
Sent: Wednesday, September 12, 2012 12:00:27 PM
Subject: Re: Re: [Pulsar-Aviators] 912 Hiccup
p { margin: 0; }
My manuals never mentioned mounting the fuel pump at 45 degrees or routing fuel back to the tank via a return line. As a matter of fact, there were no provisions in the end plates for a fuel return or a selector switch for feeding back to the appropriate tank. There wasn't any information on a bypass for the electric pump either.
Barry.
From: "Bernard Wilder" <bernard.wilder2(at)gmail.com>
To: pulsar-list(at)matronics.com
Sent: Wednesday, September 12, 2012 11:02:26 AM
Subject: Re: Re: [Pulsar-Aviators] 912 Hiccup
Bob,
You may remember that my initial theory was that the problem was with the electric fuel pump.
Barry,
Is your electric fuel pump mounted on a 45 degree angle ? ? ? Mine specified that it should be,
Do you have a jetted fuel line going from the fuel line between the engine fuel pump and the carbs back to your fuel cells ? ? ? Rotax standard instalation instructions specify that there be one.
Even with this bleed back path for hot fuel, and vapor formed in the fuel line when the fuel cooks off and turning on the electric fuel pump,, on a hot day when I forget to open the hatch on the top of my cowl it is common for the engine to falter four to five minutes after re-start. On such days I turn on my electric fuel pump run my engine long enough to be past the time that the engine will run on the fuel left over in the carb bowls.
Bernie Wilder
On Wed, Sep 12, 2012 at 9:27 AM, Bob Heiser <w7ikt(at)fly-web.us (w7ikt(at)fly-web.us)> wrote:
[quote] Bob,
This has some similarities to my accident. I believe the electric fuel pump blocked fuel flow in my plane. When the fuel pump was removed I could not blow thru it in either direction, should have been able to in the direction of flow. After shipping the fuel pump to the NTSB it operated normally. Do you have a bypass and check valve around the electric fuel pump?
God Bless
Bob Heiser W7IKT
On 9/10/2012 6:23 PM, Bob Hartunian wrote:
| Quote: |
Flew out locally for bkfst on Sunday, past mountains to flatlands and landed and all was fine. Got back into plane 45 min later and started up fine. Did normal runup and had 5 gal in left tank, full right tank, running off left, all was fine.
Took off normally and did another normal left crosswind turn toward home and mountains. All indications normal including fuel pressure. Climbing at 500 fpm, 100 mph, engine around 5100 rpm, when suddenly engine rpm drops to almost idle. No shaking or vibes. Immediately kicked on electric fuel pump but saw no indications for low fuel pressure, and engine came back normally. I don’t think the fuel pump really did anything as engine just regained rpm and flew perfectly all the way home for another 20 min. out over desert just in case.
I pulled cowl and checked things visually but no obvious problems. Don’t have a good explanation for why rpm dropped.
Bob H
__,_._,___
arget="_blank">http://www.matronics.com/Navigator?Pulsar-List
ttp://forums.matronics.com
_blank">http://www.matronics.com/contribution
|
arget=_blank>http://www.matronics.com/Navigator?Pulsar-List
p://forums.matronics.com
blank>http://www.matronics.com/contribution
= --> http://www.matronics.com/Navigator?Pulsar-List
; http://forums.matronics.com
blank>http://www.matronics.com/contribution
[b]
| | - The Matronics Pulsar-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Pulsar-List |
|
|
|
| Back to top |
|
|
barryjedwards(at)lineone.
Guest
|
| Posted: Wed Sep 12, 2012 8:36 am Post subject: [Pulsar-Aviators] 912 Hiccup |
|
|
The instructions about mounting my Facet pump were on the original Facet pack which I still have some 21 years later. It clearly says that it must be mounted at 45 degrees. Back in those days when we were running on leaded fuel there was less of an issue with vapour lock as the VP of that fuel was higher. When unleaded fuel became the norm, a fuel return line was mandated in the UK to avoid the possibility of vapour locking. I think Rotax also mandated it. I had to put a new return line into my right tank to facilitate this.
Barry
912 Taildragger UK 1030 hours
From: barrynorman(at)comcast.net (barrynorman(at)comcast.net)
Sent: Wednesday, September 12, 2012 5:00 PM
To: pulsar-list(at)matronics.com (pulsar-list(at)matronics.com)
Subject: Re: Re: [Pulsar-Aviators] 912 Hiccup
My manuals never mentioned mounting the fuel pump at 45 degrees or routing fuel back to the tank via a return line. As a matter of fact, there were no provisions in the end plates for a fuel return or a selector switch for feeding back to the appropriate tank. There wasn't any information on a bypass for the electric pump either.
Barry.
From: "Bernard Wilder" <bernard.wilder2(at)gmail.com>
To: pulsar-list(at)matronics.com
Sent: Wednesday, September 12, 2012 11:02:26 AM
Subject: Re: Re: [Pulsar-Aviators] 912 Hiccup
Bob,
You may remember that my initial theory was that the problem was with the electric fuel pump.
Barry,
Is your electric fuel pump mounted on a 45 degree angle ? ? ? Mine specified that it should be,
Do you have a jetted fuel line going from the fuel line between the engine fuel pump and the carbs back to your fuel cells ? ? ? Rotax standard instalation instructions specify that there be one.
Even with this bleed back path for hot fuel, and vapor formed in the fuel line when the fuel cooks off and turning on the electric fuel pump,, on a hot day when I forget to open the hatch on the top of my cowl it is common for the engine to falter four to five minutes after re-start. On such days I turn on my electric fuel pump run my engine long enough to be past the time that the engine will run on the fuel left over in the carb bowls.
Bernie Wilder
On Wed, Sep 12, 2012 at 9:27 AM, Bob Heiser <w7ikt(at)fly-web.us (w7ikt(at)fly-web.us)> wrote:
[quote] Bob,
This has some similarities to my accident. I believe the electric fuel pump blocked fuel flow in my plane. When the fuel pump was removed I could not blow thru it in either direction, should have been able to in the direction of flow. After shipping the fuel pump to the NTSB it operated normally. Do you have a bypass and check valve around the electric fuel pump?
God Bless
Bob Heiser W7IKT
On 9/10/2012 6:23 PM, Bob Hartunian wrote:
| Quote: |
Flew out locally for bkfst on Sunday, past mountains to flatlands and landed and all was fine. Got back into plane 45 min later and started up fine. Did normal runup and had 5 gal in left tank, full right tank, running off left, all was fine.
Took off normally and did another normal left crosswind turn toward home and mountains. All indications normal including fuel pressure. Climbing at 500 fpm, 100 mph, engine around 5100 rpm, when suddenly engine rpm drops to almost idle. No shaking or vibes. Immediately kicked on electric fuel pump but saw no indications for low fuel pressure, and engine came back normally. I don’t think the fuel pump really did anything as engine just regained rpm and flew perfectly all the way home for another 20 min. out over desert just in case.
I pulled cowl and checked things visually but no obvious problems. Don’t have a good explanation for why rpm dropped.
Bob H
__,_._,___
arget="_blank">http://www.matronics.com/Navigator?Pulsar-List
ttp://forums.matronics.com
_blank">http://www.matronics.com/contribution
|
arget=_blank>http://www.matronics.com/Navigator?Pulsar-List
p://forums.matronics.com
blank>http://www.matronics.com/contribution
href="http://www.matronics.com/Navigator?Pulsar-List">http://www.matronhref="http://forums.matronics.com">http://forums.matronics.com
href="http://www.matronics.com/contribution">http://www.matronics.com/c
[b]
| | - The Matronics Pulsar-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Pulsar-List |
|
|
|
| Back to top |
|
|
barrynorman(at)comcast.ne
Guest
|
| Posted: Wed Sep 12, 2012 9:02 am Post subject: [Pulsar-Aviators] 912 Hiccup |
|
|
It sounds like I should go ahead and put in a return line. What did most people do for a return line? I was thinking about using a low pressure poppet valve (maybe 2-3 pounds) with a small fuel injection pill to restrict flow, installed in the fuel line before the split to the carbs and route it back to a tank. My concern is pumping to much fuel back to one tank. With poppet valve and pill, the fuel would only flow when pressure exceeded the pressure point of the poppet valve and then be restricted by the pill.
Barry
From: "Barry J Edwards" <barryjedwards(at)lineone.net>
To: pulsar-list(at)matronics.com
Sent: Wednesday, September 12, 2012 12:35:34 PM
Subject: Re: Re: [Pulsar-Aviators] 912 Hiccup
p { margin: 0; } The instructions about mounting my Facet pump were on the original Facet pack which I still have some 21 years later. It clearly says that it must be mounted at 45 degrees. Back in those days when we were running on leaded fuel there was less of an issue with vapour lock as the VP of that fuel was higher. When unleaded fuel became the norm, a fuel return line was mandated in the UK to avoid the possibility of vapour locking. I think Rotax also mandated it. I had to put a new return line into my right tank to facilitate this.
Barry
912 Taildragger UK 1030 hours
From: barrynorman(at)comcast.net (barrynorman(at)comcast.net)
Sent: Wednesday, September 12, 2012 5:00 PM
To: pulsar-list(at)matronics.com (pulsar-list(at)matronics.com)
Subject: Re: Re: [Pulsar-Aviators] 912 Hiccup
My manuals never mentioned mounting the fuel pump at 45 degrees or routing fuel back to the tank via a return line. As a matter of fact, there were no provisions in the end plates for a fuel return or a selector switch for feeding back to the appropriate tank. There wasn't any information on a bypass for the electric pump either.
Barry.
From: "Bernard Wilder" <bernard.wilder2(at)gmail.com>
To: pulsar-list(at)matronics.com
Sent: Wednesday, September 12, 2012 11:02:26 AM
Subject: Re: Re: [Pulsar-Aviators] 912 Hiccup
Bob,
You may remember that my initial theory was that the problem was with the electric fuel pump.
Barry,
Is your electric fuel pump mounted on a 45 degree angle ? ? ? Mine specified that it should be,
Do you have a jetted fuel line going from the fuel line between the engine fuel pump and the carbs back to your fuel cells ? ? ? Rotax standard instalation instructions specify that there be one.
Even with this bleed back path for hot fuel, and vapor formed in the fuel line when the fuel cooks off and turning on the electric fuel pump,, on a hot day when I forget to open the hatch on the top of my cowl it is common for the engine to falter four to five minutes after re-start. On such days I turn on my electric fuel pump run my engine long enough to be past the time that the engine will run on the fuel left over in the carb bowls.
Bernie Wilder
On Wed, Sep 12, 2012 at 9:27 AM, Bob Heiser <w7ikt(at)fly-web.us (w7ikt(at)fly-web.us)> wrote:
[quote] Bob,
This has some similarities to my accident. I believe the electric fuel pump blocked fuel flow in my plane. When the fuel pump was removed I could not blow thru it in either direction, should have been able to in the direction of flow. After shipping the fuel pump to the NTSB it operated normally. Do you have a bypass and check valve around the electric fuel pump?
God Bless
Bob Heiser W7IKT
On 9/10/2012 6:23 PM, Bob Hartunian wrote:
| Quote: |
Flew out locally for bkfst on Sunday, past mountains to flatlands and landed and all was fine. Got back into plane 45 min later and started up fine. Did normal runup and had 5 gal in left tank, full right tank, running off left, all was fine.
Took off normally and did another normal left crosswind turn toward home and mountains. All indications normal including fuel pressure. Climbing at 500 fpm, 100 mph, engine around 5100 rpm, when suddenly engine rpm drops to almost idle. No shaking or vibes. Immediately kicked on electric fuel pump but saw no indications for low fuel pressure, and engine came back normally. I don’t think the fuel pump really did anything as engine just regained rpm and flew perfectly all the way home for another 20 min. out over desert just in case.
I pulled cowl and checked things visually but no obvious problems. Don’t have a good explanation for why rpm dropped.
Bob H
__,_._,___
arget="_blank">http://www.matronics.com/Navigator?Pulsar-List
ttp://forums.matronics.com
_blank">http://www.matronics.com/contribution
|
arget=_blank>http://www.matronics.com/Navigator?Pulsar-List
p://forums.matronics.com
blank>http://www.matronics.com/contribution
href="http://www.matronics.com/Navigator?Pulsar-List">http://www.matronhref="http://forums.matronics.com">http://forums.matronics.com
href="http://www.matronics.com/contribution">http://www.matronics.com/c
arget=_blank>http://www.matronics.com/Navigator?Pulsar-List
p://forums.matronics.com
blank>http://www.matronics.com/contribution
[b]
| | - The Matronics Pulsar-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Pulsar-List |
|
|
|
| Back to top |
|
|
barryjedwards(at)lineone.
Guest
|
| Posted: Wed Sep 12, 2012 9:18 am Post subject: [Pulsar-Aviators] 912 Hiccup |
|
|
We use a simple Tee piece in the line after the fuel pump with a fine jet in the discharge line back to the tank. the hole size is 0.35mm:
http://www.ekmpowershop2.com/ekmps/shops/conairsports/fuel-return-restrictor-fsc-039-1743-p.asp
Simple and works well sending the minimum amount of fuel back to the tank.
Barry
G-XPXP
From: barrynorman(at)comcast.net (barrynorman(at)comcast.net)
Sent: Wednesday, September 12, 2012 5:56 PM
To: pulsar-list(at)matronics.com (pulsar-list(at)matronics.com)
Subject: Re: Re: [Pulsar-Aviators] 912 Hiccup
It sounds like I should go ahead and put in a return line. What did most people do for a return line? I was thinking about using a low pressure poppet valve (maybe 2-3 pounds) with a small fuel injection pill to restrict flow, installed in the fuel line before the split to the carbs and route it back to a tank. My concern is pumping to much fuel back to one tank. With poppet valve and pill, the fuel would only flow when pressure exceeded the pressure point of the poppet valve and then be restricted by the pill.
Barry
From: "Barry J Edwards" <barryjedwards(at)lineone.net>
To: pulsar-list(at)matronics.com
Sent: Wednesday, September 12, 2012 12:35:34 PM
Subject: Re: Re: [Pulsar-Aviators] 912 Hiccup
p { margin: 0; } The instructions about mounting my Facet pump were on the original Facet pack which I still have some 21 years later. It clearly says that it must be mounted at 45 degrees. Back in those days when we were running on leaded fuel there was less of an issue with vapour lock as the VP of that fuel was higher. When unleaded fuel became the norm, a fuel return line was mandated in the UK to avoid the possibility of vapour locking. I think Rotax also mandated it. I had to put a new return line into my right tank to facilitate this.
Barry
912 Taildragger UK 1030 hours
From: barrynorman(at)comcast.net (barrynorman(at)comcast.net)
Sent: Wednesday, September 12, 2012 5:00 PM
To: pulsar-list(at)matronics.com (pulsar-list(at)matronics.com)
Subject: Re: Re: [Pulsar-Aviators] 912 Hiccup
My manuals never mentioned mounting the fuel pump at 45 degrees or routing fuel back to the tank via a return line. As a matter of fact, there were no provisions in the end plates for a fuel return or a selector switch for feeding back to the appropriate tank. There wasn't any information on a bypass for the electric pump either.
Barry.
From: "Bernard Wilder" <bernard.wilder2(at)gmail.com>
To: pulsar-list(at)matronics.com
Sent: Wednesday, September 12, 2012 11:02:26 AM
Subject: Re: Re: [Pulsar-Aviators] 912 Hiccup
Bob,
You may remember that my initial theory was that the problem was with the electric fuel pump.
Barry,
Is your electric fuel pump mounted on a 45 degree angle ? ? ? Mine specified that it should be,
Do you have a jetted fuel line going from the fuel line between the engine fuel pump and the carbs back to your fuel cells ? ? ? Rotax standard instalation instructions specify that there be one.
Even with this bleed back path for hot fuel, and vapor formed in the fuel line when the fuel cooks off and turning on the electric fuel pump,, on a hot day when I forget to open the hatch on the top of my cowl it is common for the engine to falter four to five minutes after re-start. On such days I turn on my electric fuel pump run my engine long enough to be past the time that the engine will run on the fuel left over in the carb bowls.
Bernie Wilder
On Wed, Sep 12, 2012 at 9:27 AM, Bob Heiser <w7ikt(at)fly-web.us (w7ikt(at)fly-web.us)> wrote:
[quote] Bob,
This has some similarities to my accident. I believe the electric fuel pump blocked fuel flow in my plane. When the fuel pump was removed I could not blow thru it in either direction, should have been able to in the direction of flow. After shipping the fuel pump to the NTSB it operated normally. Do you have a bypass and check valve around the electric fuel pump?
God Bless
Bob Heiser W7IKT
On 9/10/2012 6:23 PM, Bob Hartunian wrote:
| Quote: |
Flew out locally for bkfst on Sunday, past mountains to flatlands and landed and all was fine. Got back into plane 45 min later and started up fine. Did normal runup and had 5 gal in left tank, full right tank, running off left, all was fine.
Took off normally and did another normal left crosswind turn toward home and mountains. All indications normal including fuel pressure. Climbing at 500 fpm, 100 mph, engine around 5100 rpm, when suddenly engine rpm drops to almost idle. No shaking or vibes. Immediately kicked on electric fuel pump but saw no indications for low fuel pressure, and engine came back normally. I don’t think the fuel pump really did anything as engine just regained rpm and flew perfectly all the way home for another 20 min. out over desert just in case.
I pulled cowl and checked things visually but no obvious problems. Don’t have a good explanation for why rpm dropped.
Bob H
__,_._,___
arget="_blank">http://www.matronics.com/Navigator?Pulsar-List
ttp://forums.matronics.com
_blank">http://www.matronics.com/contribution
|
arget=_blank>http://www.matronics.com/Navigator?Pulsar-List
p://forums.matronics.com
blank>http://www.matronics.com/contribution
href="http://www.matronics.com/Navigator?Pulsar-List">http://www.matronhref="http://forums.matronics.com">http://forums.matronics.com
href="http://www.matronics.com/contribution">http://www.matronics.com/c
arget=_blank>http://www.matronics.com/Navigator?Pulsar-List
p://forums.matronics.com
blank>http://www.matronics.com/contribution
href="http://www.matronics.com/Navigator?Pulsar-List">http://www.matronhref="http://forums.matronics.com">http://forums.matronics.com
href="http://www.matronics.com/contribution">http://www.matronics.com/c
[b]
| | - The Matronics Pulsar-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Pulsar-List |
|
|
|
| Back to top |
|
|
barrynorman(at)comcast.ne
Guest
|
| Posted: Wed Sep 12, 2012 9:34 am Post subject: [Pulsar-Aviators] 912 Hiccup |
|
|
Thanks Barry!
From: "Barry J Edwards" <barryjedwards(at)lineone.net>
To: pulsar-list(at)matronics.com
Sent: Wednesday, September 12, 2012 1:17:26 PM
Subject: Re: Re: [Pulsar-Aviators] 912 Hiccup
p { margin: 0; } We use a simple Tee piece in the line after the fuel pump with a fine jet in the discharge line back to the tank. the hole size is 0.35mm:
http://www.ekmpowershop2.com/ekmps/shops/conairsports/fuel-return-restrictor-fsc-039-1743-p.asp
Simple and works well sending the minimum amount of fuel back to the tank.
Barry
G-XPXP
From: barrynorman(at)comcast.net (barrynorman(at)comcast.net)
Sent: Wednesday, September 12, 2012 5:56 PM
To: pulsar-list(at)matronics.com (pulsar-list(at)matronics.com)
Subject: Re: Re: [Pulsar-Aviators] 912 Hiccup
It sounds like I should go ahead and put in a return line. What did most people do for a return line? I was thinking about using a low pressure poppet valve (maybe 2-3 pounds) with a small fuel injection pill to restrict flow, installed in the fuel line before the split to the carbs and route it back to a tank. My concern is pumping to much fuel back to one tank. With poppet valve and pill, the fuel would only flow when pressure exceeded the pressure point of the poppet valve and then be restricted by the pill.
Barry
From: "Barry J Edwards" <barryjedwards(at)lineone.net>
To: pulsar-list(at)matronics.com
Sent: Wednesday, September 12, 2012 12:35:34 PM
Subject: Re: Re: [Pulsar-Aviators] 912 Hiccup
p { margin: 0; } The instructions about mounting my Facet pump were on the original Facet pack which I still have some 21 years later. It clearly says that it must be mounted at 45 degrees. Back in those days when we were running on leaded fuel there was less of an issue with vapour lock as the VP of that fuel was higher. When unleaded fuel became the norm, a fuel return line was mandated in the UK to avoid the possibility of vapour locking. I think Rotax also mandated it. I had to put a new return line into my right tank to facilitate this.
Barry
912 Taildragger UK 1030 hours
From: barrynorman(at)comcast.net (barrynorman(at)comcast.net)
Sent: Wednesday, September 12, 2012 5:00 PM
To: pulsar-list(at)matronics.com (pulsar-list(at)matronics.com)
Subject: Re: Re: [Pulsar-Aviators] 912 Hiccup
My manuals never mentioned mounting the fuel pump at 45 degrees or routing fuel back to the tank via a return line. As a matter of fact, there were no provisions in the end plates for a fuel return or a selector switch for feeding back to the appropriate tank. There wasn't any information on a bypass for the electric pump either.
Barry.
From: "Bernard Wilder" <bernard.wilder2(at)gmail.com>
To: pulsar-list(at)matronics.com
Sent: Wednesday, September 12, 2012 11:02:26 AM
Subject: Re: Re: [Pulsar-Aviators] 912 Hiccup
Bob,
You may remember that my initial theory was that the problem was with the electric fuel pump.
Barry,
Is your electric fuel pump mounted on a 45 degree angle ? ? ? Mine specified that it should be,
Do you have a jetted fuel line going from the fuel line between the engine fuel pump and the carbs back to your fuel cells ? ? ? Rotax standard instalation instructions specify that there be one.
Even with this bleed back path for hot fuel, and vapor formed in the fuel line when the fuel cooks off and turning on the electric fuel pump,, on a hot day when I forget to open the hatch on the top of my cowl it is common for the engine to falter four to five minutes after re-start. On such days I turn on my electric fuel pump run my engine long enough to be past the time that the engine will run on the fuel left over in the carb bowls.
Bernie Wilder
On Wed, Sep 12, 2012 at 9:27 AM, Bob Heiser <w7ikt(at)fly-web.us (w7ikt(at)fly-web.us)> wrote:
[quote] Bob,
This has some similarities to my accident. I believe the electric fuel pump blocked fuel flow in my plane. When the fuel pump was removed I could not blow thru it in either direction, should have been able to in the direction of flow. After shipping the fuel pump to the NTSB it operated normally. Do you have a bypass and check valve around the electric fuel pump?
God Bless
Bob Heiser W7IKT
On 9/10/2012 6:23 PM, Bob Hartunian wrote:
| Quote: |
Flew out locally for bkfst on Sunday, past mountains to flatlands and landed and all was fine. Got back into plane 45 min later and started up fine. Did normal runup and had 5 gal in left tank, full right tank, running off left, all was fine.
Took off normally and did another normal left crosswind turn toward home and mountains. All indications normal including fuel pressure. Climbing at 500 fpm, 100 mph, engine around 5100 rpm, when suddenly engine rpm drops to almost idle. No shaking or vibes. Immediately kicked on electric fuel pump but saw no indications for low fuel pressure, and engine came back normally. I don’t think the fuel pump really did anything as engine just regained rpm and flew perfectly all the way home for another 20 min. out over desert just in case.
I pulled cowl and checked things visually but no obvious problems. Don’t have a good explanation for why rpm dropped.
Bob H
__,_._,___
arget="_blank">http://www.matronics.com/Navigator?Pulsar-List
ttp://forums.matronics.com
_blank">http://www.matronics.com/contribution
|
arget=_blank>http://www.matronics.com/Navigator?Pulsar-List
p://forums.matronics.com
blank>http://www.matronics.com/contribution
href="http://www.matronics.com/Navigator?Pulsar-List">http://www.matronhref="http://forums.matronics.com">http://forums.matronics.com
href="http://www.matronics.com/contribution">http://www.matronics.com/c
arget=_blank>http://www.matronics.com/Navigator?Pulsar-List
p://forums.matronics.com
blank>http://www.matronics.com/contribution
href="http://www.matronics.com/Navigator?Pulsar-List">http://www.matronhref="http://forums.matronics.com">http://forums.matronics.com
href="http://www.matronics.com/contribution">http://www.matronics.com/c
arget=_blank>http://www.matronics.com/Navigator?Pulsar-List
p://forums.matronics.com
blank>http://www.matronics.com/contribution
[b]
| | - The Matronics Pulsar-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Pulsar-List |
|
|
|
| Back to top |
|
|
Pulsar747n
Joined: 01 Jan 2011
Posts: 7
Location: Southwest Utah
|
| Posted: Wed Sep 12, 2012 9:52 am Post subject: [Pulsar-Aviators] 912 Hiccup |
|
|
How does the discharge line help with vapor locks? I thought that return lines were a good idea on injection systems.
Carlos
On Sep 12, 2012, at 10:29 AM, barrynorman(at)comcast.net (barrynorman(at)comcast.net) wrote:
[quote]Thanks Barry!
From: "Barry J Edwards" <barryjedwards(at)lineone.net (barryjedwards(at)lineone.net)>
To: pulsar-list(at)matronics.com (pulsar-list(at)matronics.com)
Sent: Wednesday, September 12, 2012 1:17:26 PM
Subject: Re: Re: [Pulsar-Aviators] 912 Hiccup
p { margin: 0; } We use a simple Tee piece in the line after the fuel pump with a fine jet in the discharge line back to the tank. the hole size is 0.35mm:
http://www.ekmpowershop2.com/ekmps/shops/conairsports/fuel-return-restrictor-fsc-039-1743-p.asp
Simple and works well sending the minimum amount of fuel back to the tank.
Barry
G-XPXP
From: barrynorman(at)comcast.net (barrynorman(at)comcast.net)
Sent: Wednesday, September 12, 2012 5:56 PM
To: pulsar-list(at)matronics.com (pulsar-list(at)matronics.com)
Subject: Re: Re: [Pulsar-Aviators] 912 Hiccup
It sounds like I should go ahead and put in a return line. What did most people do for a return line? I was thinking about using a low pressure poppet valve (maybe 2-3 pounds) with a small fuel injection pill to restrict flow, installed in the fuel line before the split to the carbs and route it back to a tank. My concern is pumping to much fuel back to one tank. With poppet valve and pill, the fuel would only flow when pressure exceeded the pressure point of the poppet valve and then be restricted by the pill.
Barry
From: "Barry J Edwards" <barryjedwards(at)lineone.net (barryjedwards(at)lineone.net)>
To: pulsar-list(at)matronics.com (pulsar-list(at)matronics.com)
Sent: Wednesday, September 12, 2012 12:35:34 PM
Subject: Re: Re: [Pulsar-Aviators] 912 Hiccup
p { margin: 0; } The instructions about mounting my Facet pump were on the original Facet pack which I still have some 21 years later. It clearly says that it must be mounted at 45 degrees. Back in those days when we were running on leaded fuel there was less of an issue with vapour lock as the VP of that fuel was higher. When unleaded fuel became the norm, a fuel return line was mandated in the UK to avoid the possibility of vapour locking. I think Rotax also mandated it. I had to put a new return line into my right tank to facilitate this.
Barry
912 Taildragger UK 1030 hours
From: barrynorman(at)comcast.net (barrynorman(at)comcast.net)
Sent: Wednesday, September 12, 2012 5:00 PM
To: pulsar-list(at)matronics.com (pulsar-list(at)matronics.com)
Subject: Re: Re: [Pulsar-Aviators] 912 Hiccup
My manuals never mentioned mounting the fuel pump at 45 degrees or routing fuel back to the tank via a return line. As a matter of fact, there were no provisions in the end plates for a fuel return or a selector switch for feeding back to the appropriate tank. There wasn't any information on a bypass for the electric pump either.
Barry.
From: "Bernard Wilder" <bernard.wilder2(at)gmail.com (bernard.wilder2(at)gmail.com)>
To: pulsar-list(at)matronics.com (pulsar-list(at)matronics.com)
Sent: Wednesday, September 12, 2012 11:02:26 AM
Subject: Re: Re: [Pulsar-Aviators] 912 Hiccup
Bob,
You may remember that my initial theory was that the problem was with the electric fuel pump.
Barry,
Is your electric fuel pump mounted on a 45 degree angle ? ? ? Mine specified that it should be,
Do you have a jetted fuel line going from the fuel line between the engine fuel pump and the carbs back to your fuel cells ? ? ? Rotax standard instalation instructions specify that there be one.
Even with this bleed back path for hot fuel, and vapor formed in the fuel line when the fuel cooks off and turning on the electric fuel pump,, on a hot day when I forget to open the hatch on the top of my cowl it is common for the engine to falter four to five minutes after re-start. On such days I turn on my electric fuel pump run my engine long enough to be past the time that the engine will run on the fuel left over in the carb bowls.
Bernie Wilder
On Wed, Sep 12, 2012 at 9:27 AM, Bob Heiser <w7ikt(at)fly-web.us (w7ikt(at)fly-web.us)> wrote:
| Quote: | Bob,
This has some similarities to my accident. I believe the electric fuel pump blocked fuel flow in my plane. When the fuel pump was removed I could not blow thru it in either direction, should have been able to in the direction of flow. After shipping the fuel pump to the NTSB it operated normally. Do you have a bypass and check valve around the electric fuel pump?
God Bless
Bob Heiser W7IKT
On 9/10/2012 6:23 PM, Bob Hartunian wrote:
| Quote: |
Flew out locally for bkfst on Sunday, past mountains to flatlands and landed and all was fine. Got back into plane 45 min later and started up fine. Did normal runup and had 5 gal in left tank, full right tank, running off left, all was fine.
Took off normally and did another normal left crosswind turn toward home and mountains. All indications normal including fuel pressure. Climbing at 500 fpm, 100 mph, engine around 5100 rpm, when suddenly engine rpm drops to almost idle. No shaking or vibes. Immediately kicked on electric fuel pump but saw no indications for low fuel pressure, and engine came back normally. I don’t think the fuel pump really did anything as engine just regained rpm and flew perfectly all the way home for another 20 min. out over desert just in case.
I pulled cowl and checked things visually but no obvious problems. Don’t have a good explanation for why rpm dropped.
Bob H
__,_._,___
arget="_blank">http://www.matronics.com/Navigator?Pulsar-List
ttp://forums.matronics.com
_blank">http://www.matronics.com/contribution
|
arget=_blank>http://www.matronics.com/Navigator?Pulsar-List
p://forums.matronics.com
blank>http://www.matronics.com/contribution
href="http://www.matronics.com/Navigator?Pulsar-List">http://www.matronhref="http://forums.matronics.com">http://forums.matronics.com
href="http://www.matronics.com/contribution">http://www.matronics.com/c
arget=_blank>http://www.matronics.com/Navigator?Pulsar-List
p://forums.matronics.com
blank>http://www.matronics.com/contribution
href="http://www.matronics.com/Navigator?Pulsar-List">http://www.matronhref="http://forums.matronics.com">http://forums.matronics.com
href="http://www.matronics.com/contribution">http://www.matronics.com/c
arget=_blank>http://www.matronics.com/Navigator?Pulsar-List
p://forums.matronics.com
blank>http://www.matronics.com/contribution
href="http://www.matronics.com/Navigator?Pulsar-List">http://www.matronics.com/Navigator?Pulsar-List
href="http://forums.matronics.com">http://forums.matronics.com
href="http://www.matronics.com/contribution">http://www.matronics.com/contribution
|
[b]
| | - The Matronics Pulsar-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Pulsar-List |
|
|
|
| Back to top |
|
|
bernard.wilder2(at)gmail.
Guest
|
| Posted: Wed Sep 12, 2012 10:29 am Post subject: [Pulsar-Aviators] 912 Hiccup |
|
|
Barry,
When you say nothing in the manuals, are you referring to Aero Design or Sky Star manuals ? ? ? ? ?
I found nothing there either. It was in the Rotax installation manual. I checked it out with the Ratax rep ((Senior brain fart - can't say his name right now.)). that used to come to the Pulsar gatherings in Lawrence. He confirmed that I should install one.
Dumby me, at first I connected it to one fuel cell. I was using the other fuel cell and the feedback line filled the fuel cell and fuel began to run out the vent. You have to put the feed back in a "T" in the fuel line after the selector switch. That way, whichever fuel cell you are using, the fuel will feed back there.
The manual specified the size jet to use. I found the right size jet at a propane gas furnace repair facility and fashioned a way to put it in series with the feedback line. Forget how I did it but I could take a look at it and let you know if you are interested.
Bernie Wilder
n Wed, Sep 12, 2012 at 12:00 PM, <barrynorman(at)comcast.net (barrynorman(at)comcast.net)> wrote:
[quote]
My manuals never mentioned mounting the fuel pump at 45 degrees or routing fuel back to the tank via a return line. As a matter of fact, there were no provisions in the end plates for a fuel return or a selector switch for feeding back to the appropriate tank. There wasn't any information on a bypass for the electric pump either.
Barry.
From: "Bernard Wilder" <bernard.wilder2(at)gmail.com (bernard.wilder2(at)gmail.com)>
To: pulsar-list(at)matronics.com (pulsar-list(at)matronics.com)
Sent: Wednesday, September 12, 2012 11:02:26 AM
Subject: Re: Re: [Pulsar-Aviators] 912 Hiccup
Bob,
You may remember that my initial theory was that the problem was with the electric fuel pump.
Barry,
Is your electric fuel pump mounted on a 45 degree angle ? ? ? Mine specified that it should be,
Do you have a jetted fuel line going from the fuel line between the engine fuel pump and the carbs back to your fuel cells ? ? ? Rotax standard instalation instructions specify that there be one.
Even with this bleed back path for hot fuel, and vapor formed in the fuel line when the fuel cooks off and turning on the electric fuel pump,, on a hot day when I forget to open the hatch on the top of my cowl it is common for the engine to falter four to five minutes after re-start. On such days I turn on my electric fuel pump run my engine long enough to be past the time that the engine will run on the fuel left over in the carb bowls.
Bernie Wilder
On Wed, Sep 12, 2012 at 9:27 AM, Bob Heiser <w7ikt(at)fly-web.us (w7ikt(at)fly-web.us)> wrote:
| Quote: | Bob,
This has some similarities to my accident. I believe the electric fuel pump blocked fuel flow in my plane. When the fuel pump was removed I could not blow thru it in either direction, should have been able to in the direction of flow. After shipping the fuel pump to the NTSB it operated normally. Do you have a bypass and check valve around the electric fuel pump?
God Bless
Bob Heiser W7IKT
On 9/10/2012 6:23 PM, Bob Hartunian wrote:
| Quote: |
Flew out locally for bkfst on Sunday, past mountains to flatlands and landed and all was fine. Got back into plane 45 min later and started up fine. Did normal runup and had 5 gal in left tank, full right tank, running off left, all was fine.
Took off normally and did another normal left crosswind turn toward home and mountains. All indications normal including fuel pressure. Climbing at 500 fpm, 100 mph, engine around 5100 rpm, when suddenly engine rpm drops to almost idle. No shaking or vibes. Immediately kicked on electric fuel pump but saw no indications for low fuel pressure, and engine came back normally. I don’t think the fuel pump really did anything as engine just regained rpm and flew perfectly all the way home for another 20 min. out over desert just in case.
I pulled cowl and checked things visually but no obvious problems. Don’t have a good explanation for why rpm dropped.
Bob H
__,_._,___
arget="_blank">http://www.matronics.com/Navigator?Pulsar-List
ttp://forums.matronics.com
_blank">http://www.matronics.com/contribution
|
|
| Quote: |
arget="_blank">http://www.matronics.com/Navigator?Pulsar-List
ttp://forums.matronics.com
_blank">http://www.matronics.com/contribution
|
[b]
| | - The Matronics Pulsar-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Pulsar-List |
|
|
|
| Back to top |
|
|
ronko(at)att.net
Guest
|
| Posted: Wed Sep 12, 2012 11:14 am Post subject: [Pulsar-Aviators] 912 Hiccup |
|
|
Barry,
Fixing a different fuel and engine run problem, I experienced what you refer to as fuel boil with my 582. The side of the engine compartment with a gascolator, the carburetors and their fuel lines would get so hot on hot days that when I stopped the engine, I could hear the gurgle of the fuel at a boil. If I quickly jumped out, opened the cowling, I could see a bubble (vacuum) bounce in the fuel line(s). It also seems line the hottest thing of my engine, the muffler, sits right below the plumbing of the auxiliary fuel pump, gascolator and a major portion of the fuel line route, so when the engine is off, the convection of heat naturally wants to rise, but gets held in place by the cowling.
I solved my problem by improving the the source of cool air. All of the air feeding the carburetors, and cooling the fuel distribution would go through the radiator at the left cowling air inlet. It was sealed well at top and bottom by its fiberglass mounts and then on the left and right with heavy flexible, carefully cut to fit baffling material that was glued to the radiator sides (solved over-heating during taxiing on hot days). I removed one side of the baffling material to allow cool fresh air to this boiling fuel problem side. I don't have a boiling fuel problem anymore and fortunately can still taxi on 90+ degree days without ever over heating.
I hope this is of help. Try to get more cool air to the boiling fuel areas.
Ronko
From: "barrynorman(at)comcast.net" <barrynorman(at)comcast.net>
To: pulsar-list(at)matronics.com
Sent: Wed, September 12, 2012 9:19:14 AM
Subject: Re: Pulsar-List: Re: [Pulsar-Aviators] 912 Hiccup
p {margin:0;}
I had an event this summer that was similiar but I don't think it had anything to do with the fuel pump. It was a fairly warm day and I had taken my son up for a ride in the Pulsar III and returned after a 30 minute flight where everything was perfectly normal. I shut the plane down for a few minutes while we loaded another passenger and had a very difficult time restarting the plane. This was not anything new in this situation as I think the fuel starts to boil in the bowls making it difficult to start and get fresh fuel in due to the pressure in the bowls. I finally got it started and it ran rough for a few minutes but cleared up. I taxied to the runway and as I fed in power for takeoff, the RPM dropped and the engine quit. The plane refused to restart so I brought it back to the hanger. I came back the next day and the plane started right up and ran fine. This is a pattern I've noticed on my plane that appears to be vapor lock on warm days. Once those carb bowls get heat soaked from sitting, the problem shows up.
Barry
From: "Bob Heiser" <w7ikt(at)fly-web.us>
To: pulsar-list(at)matronics.com
Sent: Wednesday, September 12, 2012 9:27:00 AM
Subject: Re: [Pulsar-Aviators] 912 Hiccup
Bob,
This has some similarities to my accident. I believe the electric fuel pump blocked fuel flow in my plane. When the fuel pump was removed I could not blow thru it in either direction, should have been able to in the direction of flow. After shipping the fuel pump to the NTSB it operated normally. Do you have a bypass and check valve around the electric fuel pump?
God Bless
Bob Heiser W7IKT
On 9/10/2012 6:23 PM, Bob Hartunian wrote:
| Quote: |
Flew out locally for bkfst on Sunday, past mountains to flatlands and landed and all was fine. Got back into plane 45 min later and started up fine. Did normal runup and had 5 gal in left tank, full right tank, running off left, all was fine.
Took off normally and did another normal left crosswind turn toward home and mountains. All indications normal including fuel pressure. Climbing at 500 fpm, 100 mph, engine around 5100 rpm, when suddenly engine rpm drops to almost idle. No shaking or vibes. Immediately kicked on electric fuel pump but saw no indications for low fuel pressure, and engine came back normally. I don’t think the fuel pump really did anything as engine just regained rpm and flew perfectly all the way home for another 20 min. out over desert just in case.
I pulled cowl and checked things visually but no obvious problems. Don’t have a good explanation for why rpm dropped.
Bob H
__,_._,___
arget=_blank>http://www.matronics.com/Navigator?Pulsar-List p://forums.matronics.com blank>http://www.matronics.com/contribution |
http://www.matronics.com/Navigator?Puls======================= [/b][b]
| | - The Matronics Pulsar-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Pulsar-List |
|
|
|
| Back to top |
|
|
barrynorman(at)comcast.ne
Guest
|
| Posted: Wed Sep 12, 2012 11:49 am Post subject: [Pulsar-Aviators] 912 Hiccup |
|
|
Thanks for all the helpful tips. When I referred to the manuals, I was speaking of the Skystar building manuals. I'm going to redo the fuel system to include a fuel return and remounting the fuel pump and a fuel pump bypass with check valve. It's looks like I need more cool air under the cowling on hot days and I think I have a solution for that. While doing some research on it today, I found someone else who had the exact same issues in a Rotax 912s powered Dyn Aero MCR01. He had a fuel return and had the exact same symptoms as mine. Both planes have very tight cowlings. His problem turned out to be overheating of the electronic ignition on warm days. Here is the URL http://www.pprune.org/archive/index.php/t-271030.html.
I have an air scoop on the side of my cowling that I use for a ram air setup during the warm months. During the winter I take the ram air off and plug the scoop with a tennis ball. If I remove the ball, it will let a lot more cool air into the top of the cowling when not using the ram air. When this problem occurred this summer I had it plugged without the ram system making very warm in the cowling.
Thanks to all,
Barry
From: "Ron Koval" <ronko(at)att.net>
To: pulsar-list(at)matronics.com
Sent: Wednesday, September 12, 2012 3:12:54 PM
Subject: Re: Re: [Pulsar-Aviators] 912 Hiccup
Barry,
Fixing a different fuel and engine run problem, I experienced what you refer to as fuel boil with my 582. The side of the engine compartment with a gascolator, the carburetors and their fuel lines would get so hot on hot days that when I stopped the engine, I could hear the gurgle of the fuel at a boil. If I quickly jumped out, opened the cowling, I could see a bubble (vacuum) bounce in the fuel line(s). It also seems line the hottest thing of my engine, the muffler, sits right below the plumbing of the auxiliary fuel pump, gascolator and a major portion of the fuel line route, so when the engine is off, the convection of heat naturally wants to rise, but gets held in place by the cowling.
I solved my problem by improving the the source of cool air. All of the air feeding the carburetors, and cooling the fuel distribution would go through the radiator at the left cowling air inlet. It was sealed well at top and bottom by its fiberglass mounts and then on the left and right with heavy flexible, carefully cut to fit baffling material that was glued to the radiator sides (solved over-heating during taxiing on hot days). I removed one side of the baffling material to allow cool fresh air to this boiling fuel problem side. I don't have a boiling fuel problem anymore and fortunately can still taxi on 90+ degree days without ever over heating.
I hope this is of help. Try to get more cool air to the boiling fuel areas.
Ronko
From: "barrynorman(at)comcast.net" <barrynorman(at)comcast.net>
To: pulsar-list(at)matronics.com
Sent: Wed, September 12, 2012 9:19:14 AM
Subject: Re: Re: [Pulsar-Aviators] 912 Hiccup
p {margin:0;}
I had an event this summer that was similiar but I don't think it had anything to do with the fuel pump. It was a fairly warm day and I had taken my son up for a ride in the Pulsar III and returned after a 30 minute flight where everything was perfectly normal. I shut the plane down for a few minutes while we loaded another passenger and had a very difficult time restarting the plane. This was not anything new in this situation as I think the fuel starts to boil in the bowls making it difficult to start and get fresh fuel in due to the pressure in the bowls. I finally got it started and it ran rough for a few minutes but cleared up. I taxied to the runway and as I fed in power for takeoff, the RPM dropped and the engine quit. The plane refused to restart so I brought it back to the hanger. I came back the next day and the plane started right up and ran fine. This is a pattern I've noticed on my plane that appears to be vapor lock on warm days. Once those carb bowls get heat soaked from sitting, the problem shows up.
Barry
From: "Bob Heiser" <w7ikt(at)fly-web.us>
To: pulsar-list(at)matronics.com
Sent: Wednesday, September 12, 2012 9:27:00 AM
Subject: Re: [Pulsar-Aviators] 912 Hiccup
Bob,
This has some similarities to my accident. I believe the electric fuel pump blocked fuel flow in my plane. When the fuel pump was removed I could not blow thru it in either direction, should have been able to in the direction of flow. After shipping the fuel pump to the NTSB it operated normally. Do you have a bypass and check valve around the electric fuel pump?
God Bless
Bob Heiser W7IKT
On 9/10/2012 6:23 PM, Bob Hartunian wrote:
| Quote: |
Flew out locally for bkfst on Sunday, past mountains to flatlands and landed and all was fine. Got back into plane 45 min later and started up fine. Did normal runup and had 5 gal in left tank, full right tank, running off left, all was fine.
Took off normally and did another normal left crosswind turn toward home and mountains. All indications normal including fuel pressure. Climbing at 500 fpm, 100 mph, engine around 5100 rpm, when suddenly engine rpm drops to almost idle. No shaking or vibes. Immediately kicked on electric fuel pump but saw no indications for low fuel pressure, and engine came back normally. I don’t think the fuel pump really did anything as engine just regained rpm and flew perfectly all the way home for another 20 min. out over desert just in case.
I pulled cowl and checked things visually but no obvious problems. Don’t have a good explanation for why rpm dropped.
Bob H
__,_._,___
arget=_blank>http://www.matronics.com/Navigator?Pulsar-List p://forums.matronics.com blank>http://www.matronics.com/contribution |
http://www.matronics.com/Navigator?Puls======================= [/b][quote]
= --> http://www.matronics.com/Navigator?Pulsar-List
; http://forums.matronics.com
blank>http://www.matronics.com/contribution
[b]
| | - The Matronics Pulsar-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Pulsar-List |
|
|
|
| Back to top |
|
|
ccoulter(at)wavecable.com
Guest
|
| Posted: Wed Sep 12, 2012 12:16 pm Post subject: [Pulsar-Aviators] 912 Hiccup |
|
|
On Wed, 12 Sep 2012 08:27:00 -0500
Bob Heiser <w7ikt(at)fly-web.us> wrote:
| Quote: | Bob,
This has some similarities to my accident. I believe
the electric fuel pump blocked fuel flow in my plane.
When the fuel pump was removed I could not blow thru it
in either direction, should have been able to in the
direction of flow. After shipping the fuel pump to the
NTSB it operated normally. Do you have a bypass and
check valve around the electric fuel pump?
*God Bless
Bob Heiser W7IKT*
On 9/10/2012 6:23 PM, Bob Hartunian wrote:
>
> Flew out locally for bkfst on Sunday, past mountains to
>flatlands and
> landed and all was fine. Got back into plane 45 min
>later and started
> up fine. Did normal runup and had 5 gal in left tank,
>full right tank,
> running off left, all was fine.
> Took off normally and did another normal left crosswind
>turn toward
> home and mountains. All indications normal including
>fuel pressure.
> Climbing at 500 fpm, 100 mph, engine around 5100 rpm,
>when suddenly
> engine rpm drops to almost idle. No shaking or vibes.
>Immediately
> kicked on electric fuel pump but saw no indications for
>low fuel
> pressure, and engine came back normally. I don't think
>the fuel pump
> really did anything as engine just regained rpm and flew
>perfectly all
> the way home for another 20 min. out over desert just in
>case.
> I pulled cowl and checked things visually but no obvious
>problems.
> Don't have a good explanation for why rpm dropped.
> Bob H
> __,_._,___
|
My Pulsar gross weight is 1060.
Clarke
| | - The Matronics Pulsar-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Pulsar-List |
|
|
|
| Back to top |
|
|
kdpalmer(at)mweb.co.za
Guest
|
| Posted: Wed Sep 12, 2012 6:13 pm Post subject: [Pulsar-Aviators] 912 Hiccup |
|
|
Barry,
What you must also concider is extraction and because the intake is relatively large (on a Pulsar I would say over sized) and ram fed, high pressure - the extraction should be at least three and a half times larger being low pressure (basic principal) if you don't keep to this ratio you build up a high pressure under the cowl (some people have reported bulging upper cowls) which restricts the flow.
Look at the La Presti cowls very small inlets - good size extraction ( see a RV12) they don't seem to have a problem.
Food for thought
Keith
[quote] ---
| | - The Matronics Pulsar-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Pulsar-List |
|
|
|
| Back to top |
|
|
bernard.wilder2(at)gmail.
Guest
|
| Posted: Thu Sep 13, 2012 5:22 am Post subject: [Pulsar-Aviators] 912 Hiccup |
|
|
Right on Keith - - - -
That is why I reduced the size of my cowl openings by about 50% during the
building process. The size of the cowl openings were determined when a 582
was used as power and a small radiator was mounted just behind the openings
on each side. When the 912 was introduced and the plane became an XP, the
radiators were moved to the outlet of the cowl from than the inlets.
Howver, the size of the inlet openings was not changed when the radiators
were removed.
Bernie Wilder
On Wed, Sep 12, 2012 at 10:12 PM, Keith Palmer <kdpalmer(at)mweb.co.za> wrote:
[quote] **
Barry,
What you must also concider is extraction and because the intake
is relatively large (on a Pulsar I would say over sized) and ram fed, high
pressure - the extraction should be at least three and a half times larger
being low pressure (basic principal) if you don't keep to this ratio you
build up a high pressure under the cowl (some people have reported bulging
upper cowls) which restricts the flow.
Look at the La Presti cowls very small inlets - good size
extraction ( see a RV12) they don't seem to have a problem.
Food for thought
Keith
---
| | - The Matronics Pulsar-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Pulsar-List |
|
|
|
| Back to top |
|
|
barrynorman(at)comcast.ne
Guest
|
| Posted: Thu Sep 13, 2012 7:33 am Post subject: [Pulsar-Aviators] 912 Hiccup |
|
|
Keith,
I agree that could be an issue but the openings on the Pulsar III are very small and close to the center of the prop. On top of that, on my plane the air flow is directed into an oil cooler on each side mounted at an angle with scoops that force all the air through the coolers before being directed over the cylinder jugs. This preheats the air after going through the coolers and reduces the pressure in the cowling. Currently, I think the outlet size is about the same area as the inlet size. I did have it trimmed larger when I first flew the aircraft due to warm oil temps but it negatively affected drag quite a bit and was indicated in cruise speed. To solve that problem I added the second oil cooler and re-attached the trimmed pieces on the cowling and everything was fine except this occasional warm start problem. The side scoop I have is very small, about the size of a tennis ball and it routes air through a filter and up into the top of the cowl. I have only had warm start issues with this plugged. When it's is use with the ram air attached to the carbs, there are no warm start-up issues probably because the carbs are keep cooler with the outside air flowing through them. In the winter I typically take it off and plug the scoop to avoid the possibility of carb ice. For some reason this summer, I never got around to putting the ram air on or removing the plug and the problem occurred.
I have a temperature probe in the air box and one in the top of the cowl. On any typical day, the air temperature in the top of the cowling while flying is 50 F degrees warmer than the air in the air box that feeds the carbs. On a summer day at 6000 feet, it's normal to see 150 F temperature in cowling next to the carbs but only 100 degrees in the airbox. I'm sure that goes way up when the plane is stopped with a hot engine.
Barry
From: "Keith Palmer" <kdpalmer(at)mweb.co.za>
To: pulsar-list(at)matronics.com
Sent: Wednesday, September 12, 2012 10:12:44 PM
Subject: Re: Re: [Pulsar-Aviators] 912 Hiccup
 P { MARGIN: 0px }
Barry,
What you must also concider is extraction and because the intake is relatively large (on a Pulsar I would say over sized) and ram fed, high pressure - the extraction should be at least three and a half times larger being low pressure (basic principal) if you don't keep to this ratio you build up a high pressure under the cowl (some people have reported bulging upper cowls) which restricts the flow.
Look at the La Presti cowls very small inlets - good size extraction ( see a RV12) they don't seem to have a problem.
Food for thought
Keith
[quote] ---
| | - The Matronics Pulsar-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Pulsar-List |
|
|
|
| Back to top |
|
|
|
|
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum
|
Powered by phpBB © 2001, 2005 phpBB Group
|
Get Email Distribution Too!
FAQ
Search
Memberlist
Usergroups
Register
Profile
Log in to check your private messages
Log in
