Johnson 225 rough running

[anglosax]

I have a Johnson 225 -1995 vintage - running rough and progressively getting less and less power at the top end. The engine struggles to idle and usually dies out but will restart when hot. At low to mid range revs 1500-2000 it gives an intermittant cough and emits a cloud of blue/white smoke but continues to run with a misfire. This cough happens around every 60 secs or so . I have checked the plugs and connectors - where do I go from here?

 

[HighTrim]

Re: Johnson 225 rough running

One or more of your carbs may be running lean.

Stick 2 fingers into the carb throats, 1 at a tiime, to see if that clears up the mild backfire. You are acting as a manual choke of sorts. If that clears it up, you found your problem carb.

Have you checked the compression?

 

[dingbat]

Re: Johnson 225 rough running

Are you sure your white smoke isn't a puff of steam? I had a similar issues and it turned out to be a leaking head gasket.

 

[anglosax]

Re: Johnson 225 rough running

Had the same thought about head gasket - will do carb & comp test and getback