1996 25 hp Johonson Running Rough

[JIM4475]

I rebuilt the carb, had it adjusted by a boat mechanic took it out today and it will idle smooth and will run on plane for aprox 8-10 minutes, then it sputters and dies down like there is trash in the carb. It will run at idle speed fine when you give it gas is when it starts acting up. I have pulled out the bottom orifice and checked there is no trash, tried a new fuel line and different fuel tank. Still no difference, if I let it sit for about an hr and cool down it will run good for 8-10 minutes again. I'm stumped, this is getting frustrating. Thanks in advance for any ideas and help.

 

[tashasdaddy]

Re: 1996 25 hp Johonson Running Rough

did you do all of this when you did the carbs? http://forums.iboats.com/showthread.php?t=244013 have you check spark on both cylinders when it starts acting up. could be coil failing and running on one cylinder. are you sure it is not running hot? it really sounds like a coil getting hot and failing, then cooling off and working again. find which one is failing, then completely swap positions with the other coil, if the no spark follows the coil replace the coil, if the no spark stays with the cylinder, then investigate the power pack.

 

[JIM4475]

Re: 1996 25 hp Johonson Running Rough

I did check the spark but not when it was acting up. I spoke with my mechanic and that was what he suggested also. I have a feeling it is a coil.