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jpspencer(at)cableone.net
Guest

Posted: Wed Jan 13, 2010 2:41 pm Post subject: Fuel pump failure

Those who have had the  engine driven fuel pump fail on a 912S...what were the indications before the  failure, if any? 

 The pressure on mine is  fluctuating between the normal 5 psi and about 4 psi. I have checked all the  normal suspects.

 thx  Joe

   [quote][b]

Roger Lee

Joined: 10 Jan 2006
Posts: 1464
Location: Tucson, Az.

Posted: Wed Jan 13, 2010 3:27 pm Post subject: Re: Fuel pump failure

Hi Joe,



The normal fuel pressure is anywhere from 2.2 (low) -5.8 (max) psi.  Most run from 3.2-4.6 psi. If yours has been higher that's ok, but a fuel pressure between 3.1 - 4.6 is very normal.  Mine is only 3.4 - 3.6 psi. The other thing is where is your fuel pressure sensor mounted? Do you have a fuel pressure dampener in line between the sender and the panel? If your fuel pressure sender is mounted on top of the fuel cross over line between the carbs then vibration is your enemy and many people are remote mounting them which is Rotax approved. One last thing are you a high wing or low wing and are you running an electric auxiliary pump?

_________________
Roger Lee
Tucson, Az.
Rotax Instructor & Rotax IRC
Light Sport Repairman
Home 520-574-1080 TRY HOME FIRST
Cell 520-349-7056

Mike Hoffman

Joined: 11 Mar 2006
Posts: 54

Posted: Thu Jan 14, 2010 2:30 am Post subject: Re: Fuel pump failure

Yes, my pump failed at 8 hours. It was leaking fuel from the pump body vent hole. I found fuel stain on the front of my cowl and engine. I was told by lockwood aviation that is a problem with the pumps and that 1 out of 4 are bad. I have been waiting for my new pump since before Christmas and was told it could be 1 or 2 more weeks.

Ivor Phillips

Joined: 16 Jan 2006
Posts: 253
Location: London UK

Posted: Thu Jan 14, 2010 5:32 am Post subject: Fuel pump failure

Hi mike



You can obtain a better quality pump from



http://www.billetpump.com

TBO of more than 2800 hours

ivor

---- Mike Hoffman <mhoffman9(at)tampabay.rr.com> wrote: 

 	  Quote: 	
		   

 

 Yes, my pump failed at 8 hours. It was leaking fuel from the pump body vent hole. I found fuel stain on the front of my cowl and engine. I was told by lockwood aviation that is a problem with the pumps and that 1 out of 4 are bad. I have been waiting for my new pump since before Christmas and was told it could be 1 or 2 more weeks.

 

 

 

 

 Read this topic online here:

 

 http://forums.matronics.com/viewtopic.php?p 81402#281402

jpspencer(at)cableone.net
Guest

Posted: Thu Jan 14, 2010 5:47 am Post subject: Fuel pump failure

>Hi Joe,



 	  Quote: 	
		  The normal fuel pressure is anywhere from 2.2 (low)  -5.8 (max) psi.  Most run from

3.2-4.6 psi. If yours has been higher  that's ok, but a fuel pressure between
	


3.1 - 4.6 is very normal.  Mine  is only 3.4 - 3.6 psi. The other thing is where

is your fuel pressure sensor  mounted? Do you have a fuel pressure dampener

in line between the sender and  the panel? If your fuel pressure sender is mounted

on top of the fuel cross  over line between the carbs then vibration is your

enemy and many people are  remote mounting them which is Rotax approved. One

last thing are you a high  wing or low wing and are you running an electric  auxiliary

pump?



--------

Roger Lee

  

 Thanks for the replies and  info...it's not so much the psi the pump is putting out as the fact that the psi  is fluctuating (between 4.2 and 5.0 psi). My gauge is a direct read gauge with  the pressure pickoff just upstream of the left carb. The plane is a Zenith 701.  Yes I do have a backup electric pump that puts out 3 psi; and also have gravity  feed as long as the pitch attitude isn't too high. The fluctuating pressure  reading is unaffected by the electric pump being either on or off, as expected,  as long as the pressure is above the 3 psi the electric pump puts out. The thing  quit on me last week in level flight straight and level...fuel pressure was zero  at the time of the stoppage with both pumps on, indicating either out of  gas, stopped up vents or a blockage or leak somewhere. After getting  it on the ground, the vents were open and I stuck the tanks and both of them had  enough fuel to feed in level flight. I pulled the hood and leak checked it with  the electric pump, no leaks.Pulled the fuel filter and cleaned it, it was a  little grungy and is suspect...ran it up a while on the ground and all was  normal with steady pressure, was able to get it the 3 miles to the strip altho  the fuel pressure started fluctuating enroute. Have troubleshot everything and  haven't found anything but the fuel filter so far...but am wondering if there  have been instances of a failing engine driven pump possibly causing some sort  of blockage in the pump while failing and also wondering if fluctuating pressure  is a known early warning of impending failure with this pump. It should  have gravity fed unless the fuel filter was indeed blocked or the pump was  somehow blocked

  

 Thanks  again

 Joe

   [quote][b]

Roger Lee

Joined: 10 Jan 2006
Posts: 1464
Location: Tucson, Az.

Posted: Thu Jan 14, 2010 6:23 am Post subject: Re: Fuel pump failure

Hi Joe,



Even if the mechanical pump failed the electric pump should have been more than adequate. The mechanical pumps fail open. So if the mechanical pump quit and you still ran dry then I think you have a blockage somewhere or for some reason a vent issue. A blockage can move back and forth within a line depending on fuel demand. At high flow times it flows to a choke point, when little fuel is on demand or the engine is shut off it can move or float away from the choke point until you demand a lot of flow again. I would double check my vents and flow fuel through all my fuel lines into a can or something to flush them. I would also check my carb float bowls as they can have tattletale signs of crud.

This doesn't sound like a pump problem.

_________________
Roger Lee
Tucson, Az.
Rotax Instructor & Rotax IRC
Light Sport Repairman
Home 520-574-1080 TRY HOME FIRST
Cell 520-349-7056

jpspencer(at)cableone.net
Guest

Posted: Thu Jan 14, 2010 7:43 am Post subject: Fuel pump failure

>Even if the mechanical pump  failed the electric pump should have been more  than

adequate.

 Thanks. Agreed. Also, it  should have gravity fed. 

  

 >The mechanical pumps fail  open

 This is what I was looking for.  Thanks for that info. I have gravity feed checked everything up to the  mechanical pump and am just waiting for the hangar to warm up and will do that  this morning.

  

 The pressure fluctuation is  attitude related...when lowering the nose the pressure increases from about 4.2  to about 4.7 or 4.8. Makes me think there is something floating around in there  that is blocking feed but have checked everything from the mechanical pump back  and it's all clean. The vents are definitely open, there's no water in  anything.

  

 As an aside, I am wondering about  not running a mechanical pump now, what with gravity feed available. I could  install 2 electric pumps for redundancy for steep takeoffs/climb outs where it  wouldn't gravity feed and block off the mechanical pump pad.I should be able to  get home on gravity feed if it total electric fails...do you know of any  problems with blocking it off and not running the pump?

  

 Thanks  again

 Joe

   [quote][b]

Roger Lee

Joined: 10 Jan 2006
Posts: 1464
Location: Tucson, Az.

Posted: Thu Jan 14, 2010 8:34 am Post subject: Re: Fuel pump failure

There are people that do not have the mechanical pump and have a solid gasket/plate over the opening and only run electric pumps. I saw a 914 like this the other day on a Zenith 701. Way over powered.

_________________
Roger Lee
Tucson, Az.
Rotax Instructor & Rotax IRC
Light Sport Repairman
Home 520-574-1080 TRY HOME FIRST
Cell 520-349-7056

jpspencer(at)cableone.net
Guest

Posted: Thu Jan 14, 2010 9:10 am Post subject: Fuel pump failure

Well after fooling with  this thing all morning I learned a few things that I thought I would pass  along...

 It's a Zenith 701 high  wing with a 912s. It should gravity feed and does but after going thru the fuel  valve, fuel filter, electric pump and mechanical pump there is so little flow at  the carb that I now don't consider it to be gravity feed capable. The stream out  of the line just before the carb is tiny, less than the diameter of a pencil  lead...and weak. Some of you older guys might know what I'm talking about  here.

 The filter is one of the i  think it's a purolator ones with the glass bowl and cast chrome body and a  plastic screen inside. They've been around forever and I always liked them for  certain apps. But the cast body means rather thick walled nipples and a small  flow hole, further restricting the flow. I subbed in a length of 1/4 OD .035  wall tube for the filter and the flow is still too weak for comfort for this old  guy...

 FWIW

 Joe

   [quote][b]

Guy Buchanan

Joined: 16 Jul 2006
Posts: 1204
Location: Ramona, CA

Posted: Thu Jan 14, 2010 9:56 am Post subject: Fuel pump failure

At 09:05 AM 1/14/2010, you wrote:

 	  Quote: 	
		  The filter is one of the i think it's a purolator ones with the 

glass bowl and cast chrome body and a plastic screen inside.


	


I've had problems with these "gumming up". Try a new filter element 

and see if the flow is any different. Don't know why they blocked but 

I had it happen the three of them.

Guy Buchanan

San Diego, CA

K-IV 1200 / 582-C / Warp / 400 hrs. and counting

_________________
Guy Buchanan
Deceased K-IV 1200
A glider pilot too.

Roger Lee

Joined: 10 Jan 2006
Posts: 1464
Location: Tucson, Az.

Posted: Thu Jan 14, 2010 11:04 am Post subject: Re: Fuel pump failure

Hi Joe,



I'm with Guy. First thing is toss the old filter element. Then go back at the start of the flow at the fuel tank and start finding out why it is such a weak flow. If I open my gasolator my fuel just pours out and a solid stream which is before the pump. Then pop off the float bowls and see what kind of flow there is at that point. Start at point "A" and work you way through the system until you can say this is my choke point or obstruction. I bet along the way you'll find something. Is this something that just started out of the blue?

_________________
Roger Lee
Tucson, Az.
Rotax Instructor & Rotax IRC
Light Sport Repairman
Home 520-574-1080 TRY HOME FIRST
Cell 520-349-7056

Ivor Phillips

Joined: 16 Jan 2006
Posts: 253
Location: London UK

Posted: Thu Jan 14, 2010 12:41 pm Post subject: Fuel pump failure

Hi Roger



I have a 914 with electric pumps, but if you remove the blanking plate you will find a fuel pump Cam to drive a mechanical pump,

ivor



---- Roger Lee <ssadiver1(at)yahoo.com> wrote: 

 	  Quote: 	
		   

 

 There are people that do not have the mechanical pump and have a solid gasket/plate over the opening and only run electric pumps. I saw a 914 like this the other day on a Zenith 701. Way over powered.

 

 --------

 Roger Lee

 Tucson, Az.

 Light Sport Repairman - Maintenance Rated

 Rotax Repair Center

 520-574-1080

 

 

 

 

 Read this topic online here:

 

 http://forums.matronics.com/viewtopic.php?p 81471#281471

jpspencer(at)cableone.net
Guest

Posted: Thu Jan 14, 2010 12:45 pm Post subject: Fuel pump failure

Thanks  guys

 I have been thru the fuel  plumbing twice now and in some areas 3 times. I had hoped to find something  definite. The loss of flow begins in the climb from the cockpit floor to the  mechanical fuel pump(that is a long uninterrupted run of 1/4 ID tubing that I  have taken apart and blown thru 3 times, each time giving it a final check by  blowing thru it with my mouth...it is clear, no kinks, no obstructions) and  gets increasingly weak from the floor forward. There is no definite choke point  but looks to be a gradual and natural loss of flow from I guess distance from  the tank, friction of the flow thru the lines and the climb of the lines and  resulting loss of head pressure. By the time it gets to the carbs it is really  weak, as reported earlier. I realize this sounds theoretically incorrect, and I  would be skeptical if I wasn't the one that has seen it and is reporting it.  There is full flow at every point prior to that run of tubing where the line  starts its climb. As a final check I hooked up a fresh clear line at the point  where the loss of flow begins and held it outside the plane at varying heights  beginning at floor level and gradually raised it to mechanical pump  level...there was a definite loss of flow as the test tube was raised,  corresponding to what I saw with the installed line. 

 Come to think of it, all  of the gravity flow planes I have ever flown had a bottom mounted carb with no  climbs in the lines. I've got plenty of flow at the bottom

  

 Joe

   [quote][b]

Roger Lee

Joined: 10 Jan 2006
Posts: 1464
Location: Tucson, Az.

Posted: Thu Jan 14, 2010 2:04 pm Post subject: Re: Fuel pump failure

Hi Joe,



Read my last comment, maybe it should be up front.



You may want to re-plumb up to the mechanical pump. I use 8 mm (5/16) line up to the pump then it is reduced down. I would use at least 5/16 from every where up to the pump. 1/4 with a long run can be too small. If you look at a Rotax fuel pump the line in port is bigger than the line out port. This is a fairly standard fuel line setup. I know some use 1/4" all the way through, but it isn't supposed to be that way if you read Rotax writings. Larger up to the pump then reduce it down to the carbs.

You may want to buy a cheap pressure gauge from 0-10 psi and put this in line before the carbs and check the pressure. That will give you some more info. 



My other questions are how many hours on the engine and how many hours on the carbs since a rebuild or tear down inspection? You didn't say if this is a new issue after many hours of run time or has been an issue up front?

One last thought or maybe it should be one of the first thoughts. Do you have a recirculation line back to your gascolator or tanks. If you happen to get a vapor lock in the right place the pressure will drop to zero. These pumps can't pump air. The start of vapor lock will mimic these symptoms.

_________________
Roger Lee
Tucson, Az.
Rotax Instructor & Rotax IRC
Light Sport Repairman
Home 520-574-1080 TRY HOME FIRST
Cell 520-349-7056

jpspencer(at)cableone.net
Guest

Posted: Thu Jan 14, 2010 4:47 pm Post subject: Fuel pump failure

Hi Joe,



 	  Quote: 	
		  Read my last comment, maybe it should be up  front.


	


 	  Quote: 	
		  You may want to re-plumb up to the mechanical pump. I use 8 mm  (5/16) line up to

the pump then it is reduced down. I would use at least 5/16  from every where
	


up to the pump. 1/4 with a long run can be too small. If you  look at a Rotax

fuel pump the line in port is bigger than the line out port.  This is a fairly

standard fuel line setup. I know some use 1/4" all the way  through, but it isn't

supposed to be that way if you read Rotax writings.  Larger up to the pump then

reduce it down to the carbs.

  

 Understand. I saw the bigger inlet port today when I was checking things. I  am also thinking of a way to route the lines so they don't have to climb from  the floor to the pump

  

 

 	  Quote: 	
		  You may want to buy a cheap pressure gauge from 0-10 psi and put  this in line before

the carbs and check the pressure. That will give you some  more info. 
	


  

 Right. I have that  now...it's plumbed in just upstream of the left carb. A direct reading gauge.  That's how I got all the pressure  readings/fluctuations



 	  Quote: 	
		  My other questions are how many  hours on the engine and how many hours on the carbs

since a rebuild or tear  down inspection? You didn't say if this is a new
	


issue after many hours of  run time or has been an issue up front?

  

 The engine/carbs have 160  hours since new. No problems at all til the failure last week. Carbs have never  been into.

 	  Quote: 	
		  One last thought or maybe it should be  one of the first thoughts. Do you have a

recirculation line back to your  gascolator or tanks. If you happen to get a vapor
	


lock in the right place the  pressure will drop to zero. These pumps can't

pump air. The start of vapor  lock will mimic these symptoms.

  

 No return line. On the day  of the failure it was about 35 degrees and running avgas. Had been airborne for  about an hour.

  

 I flew it about an hour  today after checking everything. No pressure fluctuations or problems of any  kind. Ran fine. I do believe it was the fuel filter now. That is the only thing  I found that might have been it. The big thing I think I learned from this is  that I don't consider it to be able to gravity feed as it is now. I would  encourage others running high wing planes that you think will gravity feed in  event of pump failure to check the flow at the carb inlets if  you haven't  already done so. After checking that I would have grounded mine if I didn't  have an electric backup pump. 

 Roger and others...thanks  for all the info and I will definitely keep it all in mind as I try to improve  the fuel system...I would like to plumb it w/o a low spot in the line routing  but that may be difficult w/o interfering with the 701 door opening.  Thinking.

 Thx  again

 Joe

  

 



 

   [quote][b]

joeing701(at)internet.is
Guest

Posted: Thu Jan 14, 2010 4:54 pm Post subject: Fuel pump failure

Hello Joe.



I also have the Zenith 701 and had the vented fuel caps provided with the kit from Zenith. The fuel was limited when the aircraft was airborne due to low pressure created on top of the wing. I had to weld a tube facing forward into the caps to help with the flow, to increase the pressure inside the wing tanks.

It has not effected the engine run, because i have the header tank D type installed and the mechanical pumps is sufficient for feeding the engine, but I have an electrical pump to transfer the fuel from the wing tanks to the header tank. Just need to get the flow started with the electrical pump and can turn it off as soon the flow starts. But most often leave it on to speed up the fuel transfer.

Just an idea.

Best of luck finding the problem.

Johann G.

Iceland.



On 14.1.2010, at 20:44, Joe Spencer wrote:

 	  Quote: 	
		  Thanks guys

I have been thru the fuel plumbing twice now and in some areas 3 times. I had hoped to find something definite. The loss of flow begins in the climb from the cockpit floor to the mechanical fuel pump(that is a long uninterrupted run of 1/4 ID tubing that I have taken apart and blown thru 3 times, each time giving it a final check by blowing thru it with my mouth...it is clear, no kinks, no obstructions) and gets increasingly weak from the floor forward. There is no definite choke point but looks to be a gradual and natural loss of flow from I guess distance from the tank, friction of the flow thru the lines and the climb of the lines and resulting loss of head pressure. By the time it gets to the carbs it is really weak, as reported earlier. I realize this sounds theoretically incorrect, and I would be skeptical if I wasn't the one that has seen it and is reporting it. There is full flow at every point prior to that run of tubing where the line starts its climb. As a final check I hooked up a fresh clear line at the point where the loss of flow begins and held it outside the plane at varying heights beginning at floor level and gradually raised it to mechanical pump level...there was a definite loss of flow as the test tube was raised, corresponding to what I saw with the installed line.

Come to think of it, all of the gravity flow planes I have ever flown had a bottom mounted carb with no climbs in the lines. I've got plenty of flow at the bottom

 

Joe

 	  Quote: 	
		  



href="http://www.matronics.com/Navigator?RotaxEngines-List">http://www.matronics.com/Navigator?RotaxEngines-List

href="http://forums.matronics.com">http://forums.matronics.com

href="http://www.matronics.com/contribution">http://www.matronics.com/contribution



	


	


 [quote][b]

craig(at)craigandjean.com
Guest

Posted: Thu Jan 14, 2010 5:38 pm Post subject: Fuel pump failure

> I would like to plumb it w/o a low spot in the line routing but  that may be difficult w/o interfering with the 701 door  opening

  

 Some 701 builders have run the lines forward  at the wing root and down along the steel tubes to the  firewall.

  

 -- Craig



   From:  owner-rotaxengines-list-server(at)matronics.com  [mailto:owner-rotaxengines-list-server(at)matronics.com] On Behalf Of Joe  Spencer

Sent: Thursday, January 14, 2010 4:41 PM

To:  RotaxEngines-List(at)matronics.com

Subject: Fuel pump  failure

 

 Hi Joe,



 	  Quote: 	
		  Read my last comment, maybe it should be up  front.


	


 	  Quote: 	
		  You may want to re-plumb up to the mechanical pump. I use 8 mm  (5/16) line up to

the pump then it is reduced down. I would use at least 5/16  from every where
	


up to the pump. 1/4 with a long run can be too small. If you  look at a Rotax

fuel pump the line in port is bigger than the line out port.  This is a fairly

standard fuel line setup. I know some use 1/4" all the way  through, but it isn't

supposed to be that way if you read Rotax writings.  Larger up to the pump then

reduce it down to the carbs.

  

 Understand. I saw the bigger inlet port today when I was checking things. I  am also thinking of a way to route the lines so they don't have to climb from  the floor to the pump

  

 

 	  Quote: 	
		  You may want to buy a cheap pressure gauge from 0-10 psi and put  this in line before

the carbs and check the pressure. That will give you some  more info. 
	


  

 Right. I have that  now...it's plumbed in just upstream of the left carb. A direct reading gauge.  That's how I got all the pressure  readings/fluctuations



 	  Quote: 	
		  My other questions are how many  hours on the engine and how many hours on the carbs

since a rebuild or tear  down inspection? You didn't say if this is a new
	


issue after many hours of  run time or has been an issue up front?

  

 The engine/carbs have 160  hours since new. No problems at all til the failure last week. Carbs have never  been into.

 	  Quote: 	
		  One last thought or maybe it should be  one of the first thoughts. Do you have a

recirculation line back to your  gascolator or tanks. If you happen to get a vapor
	


lock in the right place the  pressure will drop to zero. These pumps can't

pump air. The start of vapor  lock will mimic these symptoms.

  

 No return line. On the day  of the failure it was about 35 degrees and running avgas. Had been airborne for  about an hour.

  

 I flew it about an hour  today after checking everything. No pressure fluctuations or problems of any  kind. Ran fine. I do believe it was the fuel filter now. That is the only thing  I found that might have been it. The big thing I think I learned from this is  that I don't consider it to be able to gravity feed as it is now. I would  encourage others running high wing planes that you think will gravity feed in  event of pump failure to check the flow at the carb inlets if  you haven't  already done so. After checking that I would have grounded mine if I didn't  have an electric backup pump. 

 Roger and others...thanks  for all the info and I will definitely keep it all in mind as I try to improve  the fuel system...I would like to plumb it w/o a low spot in the line routing  but that may be difficult w/o interfering with the 701 door opening.  Thinking.

 Thx  again

 Joe

  

 



 

[quote]



href="http://www.matronics.com/Navigator?RotaxEngines-List">http://www.matronics.com/Navigator?RotaxEngines-List

href="http://forums.matronics.com">http://forums.matronics.com

href="http://www.matronics.com/contribution">http://www.matronics.com/c

[b]

jpspencer(at)cableone.net
Guest

Posted: Thu Jan 14, 2010 5:53 pm Post subject: Fuel pump failure

Johann

 Thanks for that...I have  the tubes welded on mine too, but no header tank

  

 Joe

   [quote][b]

kenryan

Joined: 20 Oct 2009
Posts: 426

Posted: Thu Jan 14, 2010 6:09 pm Post subject: Fuel pump failure

Joe said:



..I would like to plumb it w/o a low spot in the line routing but that may be difficult w/o interfering with the 701 door opening. 



I ask:



Don't you WANT a low spot as a water trap???

 











On Thu, Jan 14, 2010 at 3:40 PM, Joe Spencer <jpspencer(at)cableone.net (jpspencer(at)cableone.net)> wrote:

 [quote]       Hi Joe,



 	  Quote: 	
		  Read my last comment, maybe it should be up  front.


	


 	  Quote: 	
		  You may want to re-plumb up to the mechanical pump. I use 8 mm  (5/16) line up to

the pump then it is reduced down. I would use at least 5/16  from every where
	


up to the pump. 1/4 with a long run can be too small. If you  look at a Rotax

fuel pump the line in port is bigger than the line out port.  This is a fairly

standard fuel line setup. I know some use 1/4" all the way  through, but it isn't

supposed to be that way if you read Rotax writings.  Larger up to the pump then

reduce it down to the carbs.

  

 Understand. I saw the bigger inlet port today when I was checking things. I  am also thinking of a way to route the lines so they don't have to climb from  the floor to the pump

  

 

 	  Quote: 	
		  You may want to buy a cheap pressure gauge from 0-10 psi and put  this in line before

the carbs and check the pressure. That will give you some  more info. 
	


  

 Right. I have that  now...it's plumbed in just upstream of the left carb. A direct reading gauge.  That's how I got all the pressure  readings/fluctuations



 	  Quote: 	
		  My other questions are how many  hours on the engine and how many hours on the carbs

since a rebuild or tear  down inspection? You didn't say if this is a new
	


issue after many hours of  run time or has been an issue up front?

  

 The engine/carbs have 160  hours since new. No problems at all til the failure last week. Carbs have never  been into.

 	  Quote: 	
		  One last thought or maybe it should be  one of the first thoughts. Do you have a

recirculation line back to your  gascolator or tanks. If you happen to get a vapor
	


lock in the right place the  pressure will drop to zero. These pumps can't

pump air. The start of vapor  lock will mimic these symptoms.

  

 No return line. On the day  of the failure it was about 35 degrees and running avgas. Had been airborne for  about an hour.

  

 I flew it about an hour  today after checking everything. No pressure fluctuations or problems of any  kind. Ran fine. I do believe it was the fuel filter now. That is the only thing  I found that might have been it. The big thing I think I learned from this is  that I don't consider it to be able to gravity feed as it is now. I would  encourage others running high wing planes that you think will gravity feed in  event of pump failure to check the flow at the carb inlets if  you haven't  already done so. After checking that I would have grounded mine if I didn't  have an electric backup pump. 

 Roger and others...thanks  for all the info and I will definitely keep it all in mind as I try to improve  the fuel system...I would like to plumb it w/o a low spot in the line routing  but that may be difficult w/o interfering with the 701 door opening.  Thinking.

 Thx  again

 Joe

  

 



 

    	  Quote: 	
		  



ist" target="_blank">http://www.matronics.com/Navigator?RotaxEngines-List

tp://forums.matronics.com

_blank">http://www.matronics.com/contribution



	




[b]

Roger Lee

Joined: 10 Jan 2006
Posts: 1464
Location: Tucson, Az.

Posted: Thu Jan 14, 2010 6:38 pm Post subject: Re: Fuel pump failure

Glad it is working out. Here are a few things that may help in the future just to make your fuel delivery system a little better. Use the 5/16" line all the way to the mechanical pump. Put in a gascolator for your low spot and you can then take a fuel sample and check for water or other contamination plus it has a screen in it to help filter. Run  a recirculation line from the cross over line on top of the carbs back to one of the ports on the gascolator.

_________________
Roger Lee
Tucson, Az.
Rotax Instructor & Rotax IRC
Light Sport Repairman
Home 520-574-1080 TRY HOME FIRST
Cell 520-349-7056

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