rough running 48hp

[dynedog]

I have 1995 48hp johnson does not idle well and acts like its going to shut off when running full throttle. Motor acts like it shutting off then picks back up for a few seconds and repeats this. Does not seem to have the power it should, 40hp yamaha same size boat just runs away from us.

 

[Silvertip]

Re: rough running 48hp

Squeeze the primer bulb when it begins to bog down. If the engine picks up with the squeeze, you have a fuel pump going bad, air leak in the lines, perhaps a fuel restriction, fuel filter needs changing as just a few suggestions. Have you checked the plugs? They are like a book that explains what is going on in the engine.

Dirty carbs and weak/no spark on one cylinder will make it run rough and obviously have only half the power it would normally have.