Re: Mid 50’s Johnson 25HP runs like crap. Advice needed

[david-bartlett]

Bill,

Is the Magneto synchronized with the carb?

You didn’t mention what effect(if any) the low speed adjustment has. I suspect the idle circuit is plugged as it won’t run with the butterfly closed. All that fuel from the high speed circuit is essentially flooding the engine, so unless the low speed needle is fully closed, you need to have another look at the carb.

JMHO