[Fot] Fast idle

[Kas Kastner]

Given you are certain about the possible gasket and manifold leaks the only
place remaining is the carburetor throttle plates. The engine must get air
from somewhere to give the fast idle. They only have to be off a fraction to
allow enough air to pass to give the fast idle as there is no load on the
engine.

You just might be able to see by just removing the bells and slides of each
carb to check the plate position.That opening is pretty difficult to see from
the outside of the carb but remove the carb and shine a light at the front and
looking at the plate from the rear you will if there is a gap.

To reseat the plates, slack off the screws, tap the plates lightly and check
to see that the gap has been closed, hold tightly closed with your finger as
you tighten the plates.  I would remove each screw individually then and apply
a little Loctite unless the screws are the split end type, replace each screw
in turn, recheck  the  position with the light.

The error can happen easily on a re-build of the carbs.

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