Mercury 150 Not Running Right

[Phaedrusdijk]

I have an 84 V20 CC with an 86 Mercury Black Max 150. Its been having a bit of difficulty starting lately but it always does eventually. However, for the next ten to fifteen minutes the engine will run really rough. If you try to give it full throttle it will bog a bit and then try to accelerate - slowly - finally coming up on plane. The engine will often miss and bog and then catch and keep running smoothly.

The engine *sounds* normal but is definitely down on power. At full throttle it will only hit about 4600 RPM when it used to be around 5500. It no longer "leaps" forward but, as I said above, kind of works its way up onto plane. No way to pull a skier as is!

It seems to idle fine and, as I said, sounds ok. It just no longer seems to have that "pop" that it used to.

Any ideas on what to look for/try?

Mike

[spareparts]

check compresion and spark first, then go thru the carbs

[draglink]

What Spare said....and don't run that motor at high RPMs if its not running right. If its a carb issue, you can lean out a cylinder and pop that powerhead.