> If it sounds like it is running on 2 cylinders then it could
> be sprag clutch. Have a look in the archive there is lots of
> stuff about this. I have just changed my sprag clutch after
> only 120 hours on a 912 ul. The problem was instantly cured.
>
> Pete
Can a sprag clutch problem cause rough running after the starter is off
(i.e., sprag clutch not disengaging)? I have been ignoring the sprag
clutch/heavy-duty starter discussion, assuming that it referred only to
kickback and other problems while the starter was actively driving the
engine (problems which we haven't experienced).
Thanks to all who have offered suggestions. We have carefully set the
clutch cables so that both chokes hit their limit stops at the same time.
We have also checked the temperatures of the exhaust pipes (both by feeling
and by EGT reading) after a few seconds of rough running, and no significant
difference was found between the port and starboard sides.
Today we tried replacing the fuel in the float bowls with fresh auto gas.
No help.
After a few seconds of rough running, the port side carburetor sometimes
overflows fuel into the air box, probably because the float needle gets
shaken off of its seat. Cylinders 2 and 4 are then quickly flooded, which
can be overcome only by opening the throttle far too much. We'll try
starting with the fuel selector off, to see if we can avoid the flooding.
Dave DeFord
N135TD
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