Help with 25 Johnson

[BassCaster77]

I recently put a 1990 25hp Johnson on my boat and need advice on a problem I'm having with it. The motor will run fine for a minute or so then it will almost die, then rev up again. It does this repeatedly until it finally dies completely. The only way to keep it running is if my buddy pumps the primer bulb while we're moving. I changed the primer bulb and that didn't seem to help.Do you guys think this is a problem in the motor itself such as the fuel pump or could it be an air leak somewhere in the fuel lines or tank? Any suggestions?

 

[JB]

Re: Help with 25 Johnson

It is pretty surely a fuel supply problem, BC.<br /><br />Start at the fuel tank cap vent. Then check for restrictions or air leaks in the pickup and fuel line.<br /><br />Finally, check the fuel pump. Take the fuel inlet line off the carb and put it in a clear bottle. Spin the engine over and look for firm spurts of fuel from the pump.<br /><br />An overhaul kit for the fuel pump is not expensive, but be sure to get a Manual before you try to use it.<br /><br />Good luck.

 

[BassCaster77]

Re: Help with 25 Johnson

Thanks JB, I'll try your suggestions.