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<DIV>Hey folks, thought I'd pass on a problem I experienced with my new 160 this
past weekend and share the apparent solution.</DIV>
<DIV> </DIV>
<DIV>Extremely strong engine, easy starting just like its small brother.
However, it did something very annoying this past weekend. Rich running on
theground and for the first couple passes around the field. But after about a
minute of running, the moment I would point the nose up at partial throttle, the
engine would sag to lean, and then catch and run fine again. It did this
continuously at partial throttle but not at full throttle. Oil on the exhaust
stinger was darker than I would like to see, indicating lean</DIV>
<DIV> </DIV>
<DIV>Fuel delivery was compromised somehow after the first minute or two. I did
some playing around with making certain the pump wasn't being blocked from
cooling ram air, re-plumbed the tank and everything else, used large bore tubing
throughout, etc. Problem persisted.</DIV>
<DIV> </DIV>
<DIV>Took a close look at the vent's one-way valve (standard YS valve) and saw
that this was sticking. Removed it. To avoid syphoning of fuel through the
vent, I looped the vent line and secured with a tie strap forming a P
trap.</DIV>
<DIV> </DIV>
<DIV>Also increased pump pressure about 1/4 turn. These changes have helped
richen the engine to normal levels. </DIV>
<DIV> </DIV>
<DIV>MattK</DIV>
<DIV> </DIV>
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