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<DIV><FONT face=Arial size=2>I would like to share an interesting problem, one I
unknowingly created that cost me an entire afternoon of flying
yesterday.</FONT></DIV>
<DIV><FONT face=Arial size=2>after some modifications to my Temptation cheek
cowls, I moved my Sullivan crab trap fuel filter from a position I have
used</FONT></DIV>
<DIV><FONT face=Arial size=2>them in for years, between the pump and carb with
never a problem, to before the inlet of the fuel pump thinking to stop
any</FONT></DIV>
<DIV><FONT face=Arial size=2>junk from entering the pump. I had changed a number
of things, tank, vent line etc. so isolating this was difficult. On
midrange</FONT></DIV>
<DIV><FONT face=Arial size=2>throttle after a prolonged idle, the engine(Webra
145) would almost shut off and then catch and be fine on the top end, it
was</FONT></DIV>
<DIV><FONT face=Arial size=2>driving me nuts, coming out of a corner go half
stick to start slow roll, sounded like engine quit, after a number of passes
and</FONT></DIV>
<DIV><FONT face=Arial size=2>trying it after 3 turn spin it was ok but anytime a
long straight line power off the hesitation would occur. So the next time
it happened, I shut the motor down and landed. This was after about 10 take
off and landings making adjustments to the midrange</FONT></DIV>
<DIV><FONT face=Arial size=2>and high speed needles. I was inspecting for the
normal stuff, clunk in the tank, hole in a fuel line, etc. when I noticed large
air</FONT></DIV>
<DIV><FONT face=Arial size=2>bubbles in the line from the pump to the carb. I
started back tracking the things I had changed because this was a new
problem</FONT></DIV>
<DIV><FONT face=Arial size=2>Changing the fuel filter<FONT face=Arial
size=2></FONT> back to between the pump and carb fixed the
problem</FONT><FONT face=Arial size=2>, I guess it worked as a air chamber and
was making the pump loose its prime. moral of the story, if it ain't broke,
leave it the hell alone!</FONT></DIV>
<DIV><FONT face=Arial size=2> </FONT></DIV>
<DIV><FONT face=Arial size=2>Oh while I am typing, a Greves pipe on OS 140
set at 28 inchs, add 2 extra head shims produces a solid 7800 rpm with
17x12</FONT></DIV>
<DIV><FONT face=Arial size=2>reg blade APC. I see a lot of rpm ranges for
this engine prop combo and anything in the 8000 and above I have found comes
off</FONT></DIV>
<DIV><FONT face=Arial size=2>the pipe on long up lines.I was running 16X12 at
8600 rpm to pull 10.9 lb Focus around 2 years ago and this Greve set up
produces</FONT></DIV>
<DIV><FONT face=Arial size=2>some serious pull on the 10.75 lb Focus I now have
it on, a lot more torque and a lot quieter you have to try it to see it for
yourselves oh fuel is 15% cool power. The engine does not seem to wind up high
rpms but it seems to stay solid in the up lines.</FONT></DIV>
<DIV><FONT face=Arial size=2>enough for now. see yas at
Muncie! PS the rpm in higher at 7/8 throttle
than at full, go figure?</FONT></DIV>
<DIV><FONT face=Arial size=2>Earl Vincent</FONT></DIV>
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