1987 Johnson 70 hp - running poorly

[natecollins]

I just rebuilt/adjusted carbs and set timing and sychronization on this motor for a friend. We took it out on the lake to run it some. The idle was running smooth and we accelerated to a high speed fine the first time. When he released the throttle back to a slow speed the engine cut out. After that, the motor was hard to start and ran rough when started. I was able to get the idle running smoothly again by adjusting the idle timing screw a little, but the motor cut out again every time we tried to increase the throttle. Do you have any suggestions?<br /><br />Thanks,<br />Nate

 

[fireman57]

Re: 1987 Johnson 70 hp - running poorly

Sounds like you still have some junk in one of the carb jets. Did you make sure that eack jet was perfectly clean? You may have crap in your tank that you are sucking back into your clean carbs too. Did you change the welsh plugs in it too? The small round silver plugs? They will harbor crap behind them.