 |
Matronics Email Lists
Web Forum Interface to the Matronics Email Lists
|
| View previous topic :: View next topic |
| Author |
Message |
rexjan(at)bigpond.com
Guest
|
 Posted: Thu Mar 02, 2006 6:09 pm Post subject: Re roiugh running |
 |
|
Engine seems to run fine until the auxiliary Facet electric fuel pump is
turned on when it appears to become over rich and run rough. But it doesn't
happen immediately, just by the end of a high speed run along the runway.
Fuel system is according to plans apart from the Facet pump near the header
tank. Thoughts are..
1. the return fuel line to the header tank may be restrictive . i.e. not
large enough outlet
2. Just too much fuel pressure.
Hi ! Kerry,
yes I would suspect too much fuel pressure. Bear in mind if you have the two fuel pumps in series [ the output of the Facet into the input of the mechanical ] the pressures are additive. ie:- if your mecanical pump pumps say 5 PSI and your Facet pump is say 4 PSI then your pressure at the carby is 9 PSI and your carby won't handle that without flooding. Check your manual for carby pressure requirements. It's probably about 6 PSI.
If your not sure what pressure you are getting at the carby it really is very easy to simply measure it.
Rex.
| | - The Matronics Kitfox-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?Kitfox-List |
|
|
|
| Back to top |
|
 |
lcfitt(at)sbcglobal.net
Guest
|
| Posted: Thu Mar 02, 2006 10:46 pm Post subject: Re roiugh running |
|
|
I think I finally get the picture. I rebuilt my carburetors at about 600
hours per recommendations. The first thing I noticed was that after a
flight and taxiing back home, I would get rough running and eventually fuel
spilling from the vent lines. I rechecked everything - float level, etc and
determined it was the float needles leaking. I called Bing for soem advice
and was told there were three needles for the Bing CV ccarbs. The black one
for the ULS, The brass one for the UL and, I believe a white one for ??. I
had the right needles, but they were leaking.
I went back to the old needle in the worst of the two carbs and flew with
that for a year, then finally went back to the original on the other side
last month during the Annual Condition Inspection - much smoother idle.
Incidentally, by the inspection criteria noted in the maint manual, the old
ones were perfectly servicable and that after the 600 hours.
Moral of this story, I think Bing has problems from time to time with this
part.
Regards,
Lowell
---
| | - The Matronics Kitfox-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?Kitfox-List |
|
|
|
| Back to top |
|
|
kerryskyring(at)hotmail.c
Guest
|
| Posted: Sun Mar 05, 2006 7:15 am Post subject: Re roiugh running |
|
|
Rex,
Many thanks and thanks to others who have replied. We do indeed have a facet
electric pump and then the standard mechanical pump in line. We have begun
investigating this by installing a temporary pressure gauge on the fuel line
to one carburettor. Will check pressure on the left side and then the right.
We are all set to do more test runs but the gliding club is having its
annual "let's get all the gliders serviced and polished and ready for the
season weekend" and has occupied the front of the hangar so we are locked in
by dismantled gliders. And another 12 inches of snow has just fallen so even
if the gliders weren't there we'd be hangar bound.
We have also discussed the problem with our local aircraft engineer who has
lots of experience on Rotax. He suggests we try really hard to isolate
whether fuel pressure is the problem and then if we still have rough running
to bring it back into the hangar, take the carburettors off and have them
completely cleaned and adjusted. His guess is that a small amount of dirt or
other foreign material has got in during the building process and is causing
problems. The fact that the (new) engine sat for 2 years without being run
may also be a contributing factor. I will report when we know more.
Kerry
| Quote: | Hi ! Kerry,
yes I would suspect too much fuel pressure. Bear in mind if
you have the two fuel pumps in series [ the output of the Facet into the
input of the mechanical ] the pressures are additive. ie:- if your
mecanical pump pumps say 5 PSI and your Facet pump is say 4 PSI then your
pressure at the carby is 9 PSI and your carby won't handle that without
flooding. Check your manual for carby pressure requirements. It's probably
about 6 PSI.
If your not sure what pressure you are getting at the carby it really is
very easy to simply measure it.
|
| | - The Matronics Kitfox-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?Kitfox-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
