Mike, not suggesting this is your problem, but I have copied and pasted a
msg from the Lycoming yahoo group. There is a fellow there from Mattituck,
that is really good at solving weird Lycoming problems. I guess he has seen
it all, sort of like Wayne with the Rebel. His name is Russel Mahlon, and I
have met him at Arlington before, and he definitely impressed me. You might
wish to join the Lycoming list, and ask him. Have included the link to that
as well.
http://groups.yahoo.com/group/lycoming
Walter
****************************************************************************
Re: Another fuel question
Do you have a /N 10-3878 carburetor? Don't know what is approved for
your STC but sounds like you might need a 10-4164-1 or a 10-3878M or
a 10-5193 instead.
Good Luck,
Mahlon
"The opinions and information provided in this and all of my posts
are hopefully helpful to you. Please use the information provided
responsibly and at your own risk."
--- In
lycoming@yahoogroups.com, ginny wilken <gwilken@...> wrote:
My new O-360 has that big shoebox of a carb, an MA5. I am breaking
in
the engine, and so obliged to run rich to keep things cool.
However,
I'm wondering if there's such a thing as too much fuel: I
experience
an occasional stumbling at certain, but different, RPMs, usually
when
I am pulling RPMs back without changing the mixture, which is
already
a lot richer than I would normally be running. The stumbling is
persistent, doesn't show up on the engine monitor, and can be
fixed
by leaning - except that I can't lean much because the CHTs are
still
high. Another clue is that it exhibits a sort of "hot start"
phenomenon, not what you'd expect from a carbureted engine: any
engine warm start will not catch right away, but will immediately
fire when the mixture is pulled out.
I have ten hours on the engine presently. This is a Skyhawk, so no
fuel pumps. I'm wondering if there is a float bowl issue, or some
other adjustment I can try making. It runs fine at full throttle,
and
there is no sign of overflow or fuel leakage around the carb.
There
is a three-cylinder priming system which works fine on cold
starts,
with mixture full rich. I expect to refine the leaning procedure
greatly as the cylinders break in, as I used to run my O-320
extremely lean, with good numbers all around.
Thanks for your thoughts,
ginny
-----Original Message-----
From:
mike.davis@dcsol.com [mailto:
mike.davis@dcsol.com] On Behalf Of
michael betti
Sent: Thursday, June 21, 2007 7:03 AM
To:
rebel-builders@dcsol.com
Subject: Re: [rebel-builders] Engine miss?
First of all this miss I talk about is not a vibration. When you loose
a plug the engine misses and vibrates, nothing like that. My prop is
76X58. From a pilots standpoint, the engine is smooth as glass up to
2400! It has noticeable vibration at any rpm above that, although the
amount of vibration seems acceptable, it is noticable. This is the
opposite of your experence for some reason. I tried cruising at 2550
the other night and the engine still has that so called miss, and there
is more vibration in the cabin, and I am running about 135 mph. My take
off rpm is 2500. I can easily red line my engine in straight and level
flight at full throttle too.
Mike
----Original Message----
From:
beep@sympatico.ca
Date: 06/20/2007 22:05
To: <
rebel-builders@dcsol.com>
Subj: Re: [rebel-builders] Engine miss?
Hi Mike !
Steve's on the right track ! The Elite we flew back from
BC to Ottawa had an O-360 and a 76 x 58" prop - just like
yours .... It definitely was not smooth below 2,500 rpm.
ALL O-360's I have flown like to run fast - they are happiest
at 2,550 - 2,650 rpm for cruise. It's the design of the engine.
I would NOT run at 2,400 with an O-360 - especially
if there is a noticeable vibration. Just a matter of time
until something breaks !
Steve is on the right track - manifold pressure increases
with pitch --- it's like driving your car up a steep hill in
high gear ! The engine is working hard, and the load
most likely is causing the shake .... and it's in the known
harmonic rpm range for O-360's ...
Try climbing to a decent altitude, set up for cruise
at 2,400+, then push to get a steady 200 - 300+ fpm descent.
this will unload the prop, and the rpm should increase,
maybe past 2,500 ---- and the shake might be gone ! If it is,
then you know for sure it's best to cruise at 2,500++.
Unloading the prop should lower manifold pressure
a bit ....
--
......bobp
http://www.prosumers.ca
http://bpatterson.qhealthbeauty.com
http://apatterson2.qhealthzone.com
-------------------------------orig.-------------------------
On Wednesday 20 June 2007 19:56, Mike Betti wrote:
58" fixed pitch prop and I don't monitor manifold pressure. Isn't it
just
vacuum on a natural aspirated engine?
Mike
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