My TR3A started idling very fast, about 22-2500 rpms. It had been running
fine. I checked/set the float levels and checked the levels after running (the
same level). I reset the needle (SM's) to make sure they were seated right and
checked centering in the jet. I checked with flow with my German made flow
meter. The forward carburetor airflow can't be slowed down sufficiently and it
idles at about 1300 rpm's when tuning the carbs. The mixture seems to be set
right at that rpms and the engine rev's very well. I've got the idle/airflow
screw on the forward carb screwed out until it is not touching and the choke
fast idle isn't touching the cam. I checked to make sure that the vacuum
advance line hasn't backed out or anything. I visually looked at the butterfly
and it appears to be closed down tight. Everything appears tightened down, so I
don't see where air would be leaking in.
I've tuned these many times without much trouble, but this one has got me
stumped.
I may spray starter fluid around the intake manifold with the engine
running to see if it speeds up, which would indicate a leak.
Any ideas?
-Bill in Tehachapi
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