Today's Message Index:
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1. 05:00 PM - Fw: engine advice needed (GOLDPILOT@AOL.COM)
2. 05:45 PM - Re: Fw: engine advice needed (Andy)
3. 05:53 PM - Re: Fw: engine advice needed (Linn Walters)
Message 1
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| Subject: | Fwd: engine advice needed |
____________________________________
From: david@newlangsyne.com
Sent: 1/22/2011 5:27:23 A.M. Pacific Standard Time
Subj: engine advice needed
Would you be kind enough to forward this to the Grumman Gang?
The guy who needs the information will be able to see it.
Thanks.
--------------------------------------------------------------
I'm looking for advice about two engines.
Tiger #1: 1979 AA-5B Lyc O-360-A4K (carbureted)
Tiger #2: 1991 AG-5B Lyc O-360-A4K (carbureted)
Each has developed the same problem, about 30 hours after being overhauled.
If the throttle is advanced rapidly, the engine sometimes (not always)
stumbles, almost dies, and THEN responds. Sounds like a problem with the
accelerator pump, doesn't it?
But...
Ops normal for the first several hours after overhaul, which used new
cylinders and included new intake manifolds.
Tiger #1 has had two new (overhauled) carbs since the problem
appeared, same problem.
Tiger #2 has had FOUR carbs since the problem appeared, same problem.
three fresh overhauled
one was the carburetor that was working fine on Tiger #1 just before
its engine went in for overhaul
We (two flying clubs) have been using the same engine shop for at least a
dozen engines over the past 15 years or more. We've followed his
recommended
break-in procedures with each engine. The only difference is that he
recommended Phillips 20W50 to break in Tiger #1 (most recent overhaul),
where
we always used Shell mineral oil before. I think Philips 20W50 oil was
used
for Tiger #2 also, but I'm not sure.
The owner has
- swapped carburetors as already described
- checked carb heat boxes
- isolated primer lines
Any ideas? I'm looking for something that
- mimics a bad accelerator pump but is something else
- didn't start until about 30 hours after engine overhaul
Thanks for your collective wisdom. This one is very frustrating.
Message 2
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| Subject: | Re: Fwd: engine advice needed |
Are the symptoms the same with the boost pump on ?
----- Original Message -----
From: GOLDPILOT@AOL.COM
To: teamgrumman-list@matronics.com
Sent: Saturday, January 22, 2011 6:57 PM
Subject: TeamGrumman-List: Fwd: engine advice needed
-------------------------------------------------------------------------
---
From: david@newlangsyne.com
To: goldpilot@aol.com
Sent: 1/22/2011 5:27:23 A.M. Pacific Standard Time
Subj: engine advice needed
Would you be kind enough to forward this to the Grumman Gang?
The guy who needs the information will be able to see it.
Thanks.
--------------------------------------------------------------
I'm looking for advice about two engines.
Tiger #1: 1979 AA-5B Lyc O-360-A4K (carbureted)
Tiger #2: 1991 AG-5B Lyc O-360-A4K (carbureted)
Each has developed the same problem, about 30 hours after being
overhauled.
If the throttle is advanced rapidly, the engine sometimes (not
always)
stumbles, almost dies, and THEN responds. Sounds like a problem
with the
accelerator pump, doesn't it?
But...
Ops normal for the first several hours after overhaul, which used
new
cylinders and included new intake manifolds.
Tiger #1 has had two new (overhauled) carbs since the problem
appeared, same problem.
Tiger #2 has had FOUR carbs since the problem appeared, same
problem.
three fresh overhauled
one was the carburetor that was working fine on Tiger #1 just
before
its engine went in for overhaul
We (two flying clubs) have been using the same engine shop for at
least a
dozen engines over the past 15 years or more. We've followed his
recommended
break-in procedures with each engine. The only difference is that
he
recommended Phillips 20W50 to break in Tiger #1 (most recent
overhaul), where
we always used Shell mineral oil before. I think Philips 20W50 oil
was used
for Tiger #2 also, but I'm not sure.
The owner has
- swapped carburetors as already described
- checked carb heat boxes
- isolated primer lines
Any ideas? I'm looking for something that
- mimics a bad accelerator pump but is something else
- didn't start until about 30 hours after engine overhaul
Thanks for your collective wisdom. This one is very frustrating.
Message 3
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| Subject: | Re: Fwd: engine advice needed |
I go with the accelerator pump too. Take the carbs off and hook up a
temporary fuel source. Exercise the accelerator pump and look at the
fuel expended in the throat. I'm guessing you'll find a poor amount of
fuel. Take the carbs apart yourselves and clean out the passage from
the pump to the throat. I'd also make sure that pump really belongs in
that carb ....... should be obvious. I doubt the rebuilders catch
either one, making the same mistake each time.
Linn
On 1/22/2011 7:57 PM, GOLDPILOT@AOL.COM wrote:
>
> ------------------------------------------------------------------------
> From: david@newlangsyne.com
> To: goldpilot@aol.com
> Sent: 1/22/2011 5:27:23 A.M. Pacific Standard Time
> Subj: engine advice needed
> Would you be kind enough to forward this to the Grumman Gang?
> The guy who needs the information will be able to see it.
> Thanks.
>
> --------------------------------------------------------------
>
> I'm looking for advice about two engines.
>
> Tiger #1: 1979 AA-5B Lyc O-360-A4K (carbureted)
> Tiger #2: 1991 AG-5B Lyc O-360-A4K (carbureted)
>
> Each has developed the same problem, about 30 hours after being
> overhauled.
>
> If the throttle is advanced rapidly, the engine sometimes (not always)
> stumbles, almost dies, and THEN responds. Sounds like a problem
> with the
> accelerator pump, doesn't it?
>
> But...
>
> Ops normal for the first several hours after overhaul, which used new
> cylinders and included new intake manifolds.
>
> Tiger #1 has had two new (overhauled) carbs since the problem
> appeared, same problem.
> Tiger #2 has had FOUR carbs since the problem appeared, same problem.
> three fresh overhauled
> one was the carburetor that was working fine on Tiger #1 just
> before
> its engine went in for overhaul
>
> We (two flying clubs) have been using the same engine shop for at
> least a
> dozen engines over the past 15 years or more. We've followed his
> recommended
> break-in procedures with each engine. The only difference is that he
> recommended Phillips 20W50 to break in Tiger #1 (most recent
> overhaul), where
> we always used Shell mineral oil before. I think Philips 20W50
> oil was used
> for Tiger #2 also, but I'm not sure.
>
> The owner has
> - swapped carburetors as already described
> - checked carb heat boxes
> - isolated primer lines
>
> Any ideas? I'm looking for something that
> - mimics a bad accelerator pump but is something else
> - didn't start until about 30 hours after engine overhaul
>
> Thanks for your collective wisdom. This one is very frustrating.
>
> *
>
>
> *
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