1978 Evinrude 4hp

[zenith1]

Need help troubleshooting this engine. I just replaced the fuel pump. The engine starts ok and runs good up to about 3/4 throttle. At that point it begins to stumble and then stalls. I thought at first maybe it was a fuel tank/line problem but I think I have eliminated those items. I do not have a manual for it so that makes it a little difficult.

 

[JB]

Re: 1978 Evinrude 4hp

For whatever reason it seems your engine is not getting enough fuel to make power at WOT.

Fuel supply is always the first suspect, but carb jets and float level setting could also be involved.

Lack of a Manual always makes it tougher. Get one.

 

[Jayboid]

Re: 1978 Evinrude 4hp

When it begins to stumble, have someone squeeze the primer bulb repeatedly. Does it stop stumbling? If so, we know that it is a fuel supply issue.

 

[zenith1]

Re: 1978 Evinrude 4hp

thanks to all who replied, I have a manual on the way, and that's a good tip about the fuel bulb that I will try.