1964 Johnson 5.5 only start on fast

[wadegreen80]

I have a 1964 5.5. It will only start and run in the fast position. Even in the fast position it only runs low rpms. Any help is appreciated.

 

[HighTrim]

Well what is the compression?

is it running on both cylinders?

Will both cylinders jump a 1/4" gap on an adjustable open air tester?

Coils not original are they?

Possible stuck or broken shock absorber.

Many things to think about.

 

[F_R]

I'm betting on it's starting and running on one cylinder.

 

[wadegreen80]

Thanks for the advise. I have it running high rpm's, but now it dies when I turn the choke off

 

[F_R]

Dirty high speed jet in bottom of carburetor, behind the hex drain plug.