1999 135 Optimax won't go over 3200 RPM's under load - no warning lights

[Abstraxx]

I recently purchased a new to me 1999 Searay 180 Dual Console with a 1999 135 Optimax with 116 Hours.
Boat and motor look like new. The story when purchased was the boat was in storage for a very long time.

Problem is the engine seems to run fine but won't go over 3200 RPM's in the water under load. Boat will rev fully when out of the water and on Muffs.

What was done before I purchased. Both fuel pumps, Battery.

What I did,
- Compression Test - All Excellent
- Changed Plugs
- Changed Water Pump
- Changed T-Stats
- Changed the lower gear oil
- Changed Fuel line from bulb to engine
- Replaced the 2 stroke oil w/ Optimax oil
- Filled the tank with 25gallons of 90Rec Fuel and added seafoam. Tank holds 35gallons so there is 10 gallons of gas I don't know the history of but it would run off of it prior to me adding.

There are no warning lights on the merc smart gauges and I know they work. Engine seems to run fine just can't get past 3200rpms and is a dog trying to get on plane.

Any advice? I read about checking for air in the fuel rail but need it explained which side and what I'm looking for exactly.

 

[Chris1956]

OK, what pitch prop do you have. I would think you would need a 17-19" pitch. More than that could cause low RPM and bad hole shot. You might look at the spark plugs as well. They should all be about the same color. If you have a black one or a real clean one, maybe that cylinder is not firing.

 

[Abstraxx]

It has a 21P on it