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frank-margie(at)worldnet.
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 Posted: Mon Sep 11, 2006 3:10 pm Post subject: Wandering RPM |
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REF:
I've got a 582 that likes to wander +/- 100-200 RPM when cruising at 5800.
(Actually, pretty much anytime.) It appears to be more than just prop
loading, as I have to chase it with the throttle, and not just the
elevator. Any ideas?
----------------------------------------------
Guy,
How old are your crank seals? They'll do funny things when just starting to leak. Email Green Sky or Lockwood and ask their advise.
Frank Clyma
Jacksonville, FL
[quote][b]
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Guy Buchanan
Joined: 16 Jul 2006
Posts: 1204
Location: Ramona, CA
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| Posted: Tue Sep 12, 2006 1:05 pm Post subject: Wandering RPM |
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At 04:09 PM 9/11/2006, you wrote:
| Quote: | REF:
I've got a 582 that likes to wander +/- 100-200 RPM when cruising at 5800.
(Actually, pretty much anytime.) It appears to be more than just prop
loading, as I have to chase it with the throttle, and not just the
elevator. Any ideas?
----------------------------------------------
Guy,
How old are your crank seals? They'll do funny things when just starting to leak. Email Green Sky or Lockwood and ask their advise.
Frank Clyma
Jacksonville, FL
|
Yes. How about 14 years old? I guess it's time for a rebuild. (But Bob Robertson already told me that.) What else happens when they start leaking?
Guy Buchanan
K-IV 1200 / 582-C / Warp / 100% done, thanks mostly to Bob Ducar.
Do not archive
[quote][b]
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_________________
Guy Buchanan
Deceased K-IV 1200
A glider pilot too. |
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joeing701(at)internet.is
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| Posted: Tue Sep 12, 2006 1:52 pm Post subject: Wandering RPM |
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Hello Guy.
When there is excessive air entering the engine via leaky seals, your
fuel mixture gets lean and the EGT will rise, which could cause seizure.
Your problem is most likely air leak if the rpm is wandering. Good luck
with the overhaul.
Regards,
Johann G.
Iceland.
Guy Buchanan wrote:
| Quote: | At 04:09 PM 9/11/2006, you wrote:
> REF:
>
> I've got a 582 that likes to wander +/- 100-200 RPM when cruising at
> 5800.
> (Actually, pretty much anytime.) It appears to be more than just prop
> loading, as I have to chase it with the throttle, and not just the
> elevator. Any ideas?
> ----------------------------------------------
> Guy,
>
> How old are your crank seals? They'll do funny things when just
> starting to leak. Email Green Sky or Lockwood and ask their advise.
>
> Frank Clyma
> Jacksonville, FL
>
Yes. How about 14 years old? I guess it's time for a rebuild. (But Bob
Robertson already told me that.) What else happens when they start
leaking?
Guy Buchanan
K-IV 1200 / 582-C / Warp / 100% done, thanks mostly to Bob Ducar.
Do not archive
*
*
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Guy Buchanan
Joined: 16 Jul 2006
Posts: 1204
Location: Ramona, CA
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| Posted: Tue Sep 12, 2006 7:09 pm Post subject: Wandering RPM |
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At 02:53 PM 9/12/2006, you wrote:
| Quote: | When there is excessive air entering the engine via leaky seals, your
fuel mixture gets lean and the EGT will rise, which could cause seizure.
Your problem is most likely air leak if the rpm is wandering.
|
How much do you think the EGT will vary?
Guy Buchanan
K-IV 1200 / 582-C / Warp / 100% done, thanks mostly to Bob Ducar.
Do not archive
| | - The Matronics RotaxEngines-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:
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_________________
Guy Buchanan
Deceased K-IV 1200
A glider pilot too. |
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joeing701(at)internet.is
Guest
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| Posted: Wed Sep 13, 2006 12:44 am Post subject: Wandering RPM |
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Hello Guy.
That all depends on how much air is entering the engine. Most likely it will
increase as you increase the rpm, but if the EGT is approaching 1200 deg F, you
should be on alert.
The EGT will always varie a little, depending on your carb needles and jets. As
you probably know, different rpm effects different needles and jets in the
carb. Lowest rpm=idle jet, mid range=jet needle+needle jet and max rpm=main
jet. The slider groove is also a factor here.
The EGT is the main instrument to monitor the fuel/air mixture. I hope this
will help in solving your problem.
Best regards,
Johann G.
Iceland.
On Tue, 12 Sep 2006 20:02:46 -0700
Guy Buchanan <bnn(at)nethere.com> wrote:
| Quote: |
At 02:53 PM 9/12/2006, you wrote:
>When there is excessive air entering the engine via leaky seals, your
>fuel mixture gets lean and the EGT will rise, which could cause seizure.
>Your problem is most likely air leak if the rpm is wandering.
How much do you think the EGT will vary?
Guy Buchanan
K-IV 1200 / 582-C / Warp / 100% done, thanks mostly to Bob Ducar.
Do not archive
|
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Guy Buchanan
Joined: 16 Jul 2006
Posts: 1204
Location: Ramona, CA
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| Posted: Wed Sep 13, 2006 9:34 am Post subject: Wandering RPM |
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At 01:44 AM 9/13/2006, you wrote:
| Quote: | That all depends on how much air is entering the engine. Most likely it will
increase as you increase the rpm, but if the EGT is approaching 1200 deg
F, you
should be on alert.
|
Thanks Johann,
I don't see an increase with RPM, indeed it decreases after the
typical mid RPM peak, so maybe I'm still good. Indeed my EGT's seem good,
within 30 degrees of each other and varying with RPM as recommended. The
only thing I wish is that the manual mixture (HACman) I purchased from
Green Sky had more range.
Guy Buchanan
K-IV 1200 / 582-C / Warp / 100% done, thanks mostly to Bob Ducar.
Do not archive
| | - The Matronics RotaxEngines-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?RotaxEngines-List |
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_________________
Guy Buchanan
Deceased K-IV 1200
A glider pilot too. |
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joeing701(at)internet.is
Guest
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| Posted: Wed Sep 13, 2006 2:39 pm Post subject: Wandering RPM |
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Hello Guy.
This is good. It almost eliminates that air is leaking inside your
engine via seals or rubber sockets, or gaskets(intake-exhaust).
How is the needle sitting in the plastic sledge in your carbs? I have
heard that people install the needle inside the sledge and under the
spring. This can causes the needle to move freely up and down and
therefore give you a wandering rpm. Before you do anything else, check
that. First in order of installation is the needle with the ring
installed sitting inside the cylinder. Then you install the cable, then
the plastic cup/sledge and finally roll the spring onto the cable with
spring sitting inside the plastic cup and sitting inside the groove on
the carb cover.
I hope this explains the installation clearly.
Sorry for not having anything else concrete to solve your problem, but
it can take some time to eliminate the obvious to find the cause.
Best regards,
Johann G.
Guy Buchanan wrote:
| Quote: |
At 01:44 AM 9/13/2006, you wrote:
> That all depends on how much air is entering the engine. Most likely
> it will
> increase as you increase the rpm, but if the EGT is approaching 1200
> deg F, you
> should be on alert.
Thanks Johann,
I don't see an increase with RPM, indeed it decreases after
the typical mid RPM peak, so maybe I'm still good. Indeed my EGT's
seem good, within 30 degrees of each other and varying with RPM as
recommended. The only thing I wish is that the manual mixture (HACman)
I purchased from Green Sky had more range.
Guy Buchanan
K-IV 1200 / 582-C / Warp / 100% done, thanks mostly to Bob Ducar.
Do not archive
|
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http://www.matronics.com/Navigator?RotaxEngines-List |
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Guy Buchanan
Joined: 16 Jul 2006
Posts: 1204
Location: Ramona, CA
|
| Posted: Wed Sep 13, 2006 6:40 pm Post subject: Wandering RPM |
|
|
At 03:40 PM 9/13/2006, you wrote:
| Quote: | How is the needle sitting in the plastic sledge in your carbs? I have
heard that people install the needle inside the sledge and under the
spring. This can causes the needle to move freely up and down and
therefore give you a wandering rpm.
|
No. It's correct. I even have the little O-ring to keep the needle from
turning.
Guy Buchanan
K-IV 1200 / 582-C / Warp / 100% done, thanks mostly to Bob Ducar.
Do not archive
| | - The Matronics RotaxEngines-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?RotaxEngines-List |
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_________________
Guy Buchanan
Deceased K-IV 1200
A glider pilot too. |
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frank-margie(at)worldnet.
Guest
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| Posted: Thu Sep 21, 2006 1:07 pm Post subject: Wandering RPM |
|
|
REF:
Guy,
| Quote: |
How old are your crank seals? They'll do funny things when just
starting to leak. Email Green Sky or Lockwood and ask their advise.
Frank Clyma
Jacksonville, FL
|
Yes. How about 14 years old? I guess it's time for a rebuild. (But Bob
Robertson already told me that.) What else happens when they start leaking?
-----------------------------------------------
A 2 stroke won't do anything right when the crank seals leak. Basically, the extra air sucked thru the seal leans out the mixture, and then your temps go up (EGT especially). Then you get all the fun stuff from an overtemp (if it goes high enuf) like engine seizure and glider practice. Sometimes you can also see an oil film on the case end where the mixture is being pushed out past the seal, it will leak in both directions. Seals just starting to go will often give intermittent/variable problems like wandering RPM and temp variations.
Sorry to be so late with my reply, been out of town.
------------------------
Just finished catching up on newer listings----you've gotten some good answers/info form other folks. However, if it were me, I'd still have the crank checked and the seals replaced, 14 years is too long for aviation use, IMHO.
Frank
[quote][b]
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