60 HP 4 stroke Mercury OB problem

[Larry Mendez]

I have a 2006 60 HP 4 stroke that I just got on a boat I bought so I do not have Any history on it, it starts up fine but some of the time when it is started it will idle rough and when I apply full throttle it will only run half power and other times when started it will idle smooth and will run full power when full throttle is applied. I just never know until I start it how it will run

 

[galamb]

Sounds like it's been sitting and there is crud in the fuel system. You might be able to take care of it with some Seafoam but more than likely you will need at least a new fuel filter and just hope that the injectors are not clogged.