Mariner 40 2 str.2002 perfect at low throttle but problems at medium or high.

[saoceallaigh]

Starts and runs perfectly at low throttle,but sluggish or conks on opening up. Gives occasional brief bursts of greater power on opening up, but loses power again almost immediately. Used fuel from last season (I know, but it never seemed to cause a problem before). I have a filter in the fuel line coming from the tank.

 

[fastjeff]

..."I have a filter in the fuel line coming from the tank. "

That might be the problem. The vacuum fuel pumps on OBs are very weak. Try bypassing it temporarily.


Jeff