55 Rude wont idle down

[old wise bison]

A 55 Rude that will start at real high Idle ,but when i bring it down to shift it dies. this engine had suffered an overheat and took out the power pak and some misc. wiring. Coils check out o.k. along with timming . It acts like an air leak ,but have gone over it looking for leak. Is there a way to prove if it is sucking air at lower speed? thanks John

 

[jonesg]

Re: 55 Rude wont idle down

Try a compression test, low compression will show up at idle and cause symptoms similar to advanced timing ( high idle speed).

I'd suspect a compression leak ,
due to the overheat stretching the bolts in the head and warping the head.

I had a similar problem, I tweaked the head bolts down and it went away.

Did you fix the waterpump?

 

[kenmyfam]

Re: 55 Rude wont idle down

Basic health check to begin with.
Compression
Spark
Fuel delivery
Spark plug condition.

Go from there.