100hp skipping or misfiring

[warrior_tim]

I have a 1971 Johnson 100hp o/b. It seems like thoughout the RPM range it will skop or misfire. Sometimes it will run great and sometimes it will not. It has me confused b/c of the inconsistency of the problem. It will run differently on the same tank of gas even. Any thoughts.

 

[JB]

Re: 100hp skipping or misfiring

I had a '66 Johnny V4 that did that, Tim.<br /><br />I learned a lot about outboards trying to track it down, with no luck until. . . <br /><br />A neighborhood teen who was a VW bug enthusiast asked me if I had eliminated arcing from a bad plug wire. He immediately pointed out a near-microscopic burn on the inside of the bonnet.<br /><br />Yup. New plug wires and no more trouble.<br /><br />That might not be your cause, but it is worth investigating.<br /><br />Good luck.

 

[warrior_tim]

Re: 100hp skipping or misfiring

Is it possible that the fuel inlet line is too small or that the tank does not have a big enough vent?