Trouble shooting issue on friends boat

bigdog · 07-19-2017, 05:26 PM

Trouble shooting issue on friends boat.

1986 Four Winns 21' bow rider
OMC outdrive

Boat is running real rough at WOT.
Boat seems to run fine at idle, even at 1/2 throttle.

Coil replaced last year.
Fresh gas
New water separating filter.
New gas filter
Just added gas additive to condition the gas and clean the carb.
Washed Flame arrester in cleaning fluid

With all this, still runs rough as described above.

Only other thing I could think of were spark plug wires loose from plugs or coil. Possibly maybe fuel pump ?

Thoughts?

07-19-2017, 05:26 PM	#1
bigdog Senior Member Join Date: Apr 2006 Location: Central MA-Gilford Posts: 1,411 Thanks: 308 Thanked 117 Times in 94 Posts	Trouble shooting issue on friends boat Trouble shooting issue on friends boat. 1986 Four Winns 21' bow rider OMC outdrive Boat is running real rough at WOT. Boat seems to run fine at idle, even at 1/2 throttle. Coil replaced last year. Fresh gas New water separating filter. New gas filter Just added gas additive to condition the gas and clean the carb. Washed Flame arrester in cleaning fluid With all this, still runs rough as described above. Only other thing I could think of were spark plug wires loose from plugs or coil. Possibly maybe fuel pump ? Thoughts?