[Hanks56Chevy]

What are possible causes of a mild 350ci missing and stalling above 4,500 RPMs? I have heard it could be one of the following:

1. Floating valves due to weak springs.
2. Carburator is to small. Bigger jets may be needed.
3. Distributor/timing is not set correctly.

Is this correct? Any other possible reasons for this happening?

[ericnova72]

Fuel pump or fuel filter may not be able to keep up with demand. Not likely a jet problem but no fuel even at the jet for this reason. Fuel line size physically too small. Plugged vent in fuel tank.- all possible

Carb too small?? Not really an issue, too small will limit power but it will still run fine as long as there is enough fuel in the float bowl, what do you think a 2 bbl carb does, causes an issue like this - NOPE

Timing and valve adjustment or valve float - Yes, quite possible.

Ignition breaking down, worn out guts or weak coil/bad plug wires - yes also possible.

[sqzbox]

Single point type distributors used to have a problem like that also. It was called point bounce. It was caused by weak or insufficient spring tension on the point set. The contact on the points would bounce from lobe to lobe on the dist. cam without fully closing and making contact.

Only cure was to double spring the points, get a hp set, or buy a dual point distributor.

[Hanks56Chevy]

Gents,

Appreciate the reply!