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Old July 23rd 03, 11:51 PM
Larry Smith
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"Rich S." wrote in message
...
Hi Troop..........

The weather forecast for Idaho today is staggering! 107° F in Boise, 108°

in
Twin Falls and 110° in Mountain Home. Montana is similar with 108°

forecast
in Helena.

Last year, on my way to OSH, I planned my fuel stops to take advantage of
autogas availability. I stopped at Pullman, WA and filled up. As we were
flying past Helena, Montana, the OAT showed 85° at 9500'. Fuel pressure

went
to zero and the electric pump (ahead of the firewall) made no difference.
Within one minute the engine quit. Not rough. QUIT.


What were you flying?

Fuel pumps work better against vapor-lock when closer to the source.

I'll spare you the details, but fortunately, as I was about to turn

downwind
for a soybean field, it had cooled off enough to restart. Cautiously, we
climbed and made our way to Helena, 25 miles distant. Draining the

autofuel
and filling up with 100 LL solved the problem.

Unless you are *absolutely* sure that your engine will not vapor lock in
extreme temperatures, do not run autogas. It is not worth the few bucks
difference. Don't worry about the 100 LL fouling a plug or two - your

plane
will still fly.

I am not looking for an discussion or argument about autogas. I use it
regularly in moderate temps. I will not use it when the mercury rises to
these levels.

Keep 'em flying,
Rich S.


Yes, mogas is more volatile, but couldn't you have mixed it with 100LL? Do
you have your firewall-forward fuel lines well-insulated with firesleeves?
A friend complained about vapor-lock until he band-it clamped that orange
silicone Aeroquip stuff on his lines. And don't forget to seal it on the
ends so that oil and fuel don't soak into the insulation. See Tony
Bingelis on Firewall Forward. Some people seal it with RTV silicone, some
with that expensive stuff Tony says to buy as a group.

Better to discuss it than not to discuss it. And then have to cuss it
later.