redvalkyrie
redvalkyrie Reader
10/7/16 4:38 p.m.

I installed two 40mm IDF Webers on my Starlet. They seem to work great except that if rev it or go full throttle and then go to neutral, the rpms are lazy or slow to return to idle. If I just tip in, just enough to not activate the pump jets, the problem doesn't happen.

I have checked the usual suspects-- vacuum leaks, weak return spring, binding linkage. Nothing.

Timing is correct. Carbs synced. The only other thing I can think is that, because the problem only occurs when the pump jets squirt, that maybe they're giving the engine enough fuel to continue idle but once that extra fuel is gradually used the idle returns to normal?

VClassics
VClassics Reader
10/7/16 5:05 p.m.

No, unnecessary fuel can't increase idle or make an engine slow to return to idle. It has to be either unauthorized air getting in (crankcase ventilation ported to the intake?) or ignition advance not backing off (a lesser effect).

redvalkyrie
redvalkyrie Reader
10/7/16 8:23 p.m.
VClassics said: No, unnecessary fuel can't increase idle or make an engine slow to return to idle. It has to be either unauthorized air getting in (crankcase ventilation ported to the intake?) or ignition advance not backing off (a lesser effect).

The crankcase is ported to the manifold. I didn't realize that this would have an effect on the Webers.

bentwrench
bentwrench Dork
10/7/16 8:39 p.m.

Sticky centrifugal advance?

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