1990 Johnson 25 hp running rough

[crabber1]

Just tuned up Carb, hoses in good shape, adjusted carb to specs, new gas with correct mixture(50:1), and replaced spark plugs. Ran motor for 15 min., pulled plugs to find the bottom one completely black and wet, and top one slightly black and wet. Plugs were getting black and wet prior to Carb tune up.

It is running better after Carb tune up, but something still is not right. Plugs should not be that way.

What next? Help!!

 

[tashasdaddy]

Re: 1990 Johnson 25 hp running rough

are you sure the float level is set properly, how far will your spark jump or a spark tester. have you ever decarbed it. check compression. done a link n sinc??????????? is it running cold.

 

[crabber1]

Re: 1990 Johnson 25 hp running rough

I am pretty sure the float level is right. I set the level when I installed the new one. I have never tested the spark, not sure how to do that.

I am not familiar with "decarbing", checking compression, or link n sinc? Are these things only a trained mechanic can do?

 

[tashasdaddy]

Re: 1990 Johnson 25 hp running rough

you need a OEM Johnson service manual outboardbooks.com these are all simple procedures.

 

[wbeaton]

Re: 1990 Johnson 25 hp running rough

Running rough and wet plugs sounds like its running rich. Did you use a carb kit or just clean everything out? If you didn't use a kit then get one, clean everything again, install the kit, reset the float and try again.