4500 RPM WTO help 85hp force

[greenoil]

I have a 89 17' Spectrum with a 85 HP force. I just put a new piston in it and did a little work on the trim. The compression checks out and are in range of each other. I use the boat at 5000ft and have jetted accourdingly. I have the smallest prop that will fit on the engine which is 13-1/2x15. The problem is that i can only get 4500 RPM and 30 mph at WTO can anybody help me get this boat running tip top. Also how do you tell if the foam is saturated with water. I live in New Mexico and think that it would be hard to get water logged.
-Shawn-

 

[MWBROWN]

Re: 4500 RPM WTO help 85hp force

Hey,

I have a 16 ft Bayliner bass type boat. 85 HP Force.

With my 13 x 15 pitch I run 6300 RPM at about 34 MPH with two 225 lb guys
and 20 gal gas.
With my 13 x 20 pitch I run 5200 RPM at about 38 MPH with two 225 lb guys.

I believe I am getting all I can out of my engine.

New plugs, new fuel pump, new fuel line, and a few cans of SeaFoam.

I hope this give you some idea of where you should be.

To me, the rpms are way low for the pitch that you have.

Mike

 

[greenoil]

Re: 4500 RPM WTO help 85hp force

I also redid the fuel pump and noticed one of the valves was completely worn out. It had turned into wire and some of the metal puntured diaphram. Do i need to replace the valve to get maximum performance?

 

[Frank Acampora]

Re: 4500 RPM WTO help 85hp force

Yes! Yes! Yes. Those are button valves and were used in all Chrysler and Force fuel pumps up to about 1990 so they should be available. It is a two stage pump with three valves. If one is bad, it will not deliver the full amount of fuel necessary at WOT. ---CAUTION!--- Remove your carbs and check the inlet needles and seats. Do it now before running the engine further. You may have metal chips clogging the seat. The hole in it is way less than 1/16 inch. If this happens to only one carb, that cylinder will run lean and melt the piston. For this reason, I ALWAYS put a disposable auto gas filter between the fuel pump and carbs. It's the best 3 buck investment you will ever make.