1989 85hp force motor

[truckergary]

i have just bought a 85hp force motor on a spectrum boat and have had nothing but trouble i have rebuilt carbs change fuel filters put new gas in engine would not rev up over 2000 rpms did more checking stator checked out bad so put in new one now i am not getting any spark to #2 cylinder changed wwire on cd boxes and spark follows my changes so i am guessing coils are good would stator take out one of the cd boxes with it when new hot spark one was replaced

 

[chuckz]

Re: 1989 85hp force motor

More likely a bad cd box would take out the stator.<br /><br />Swap CD boxes #1 and #2. The second side of #2 is not used.

 

[truckergary]

Re: 1989 85hp force motor

have tried that still no spark at #2 am guessin cd box was weak and when i put in new stator with full power it took out cd box is there a way to test cd boxes with a meter?

 

[truckergary]

Re: 1989 85hp force motor

ok i finnally got time to get this back to the water i changed the stator and one of the cd boxes got good spark put it in the water was hard starting but when i got it started it ran at 4100 rpms at 33 mph at top end is that about what this motor does or should i still keep lookin it runs good at that speed and sounds good just thought it would have more but i might be wrong anybody else know

 

[Dawg2]

Re: 1989 85hp force motor

RPM for a 1989 85hp Force should be in the 4500-5500 range usually it is best to be in upper range5500 at wide open throttle.Sounds like maybe over propped.Pull propeller off and see what diameter and pitch it is and post back and these people will be able to help you more also give size and weight of boat.

 

[roscoe]

Re: 1989 85hp force motor

Glad you got her running.<br />Dawg2 is right on.<br />How big is the boat? model?<br /><br />Best to get the rpm up 500 to 1000 more, it is healthier for the engine. With the rpm will come better holeshot and a bit more speed.<br /><br />Post the numbers found on your prop if you need help deciphering them.

 

[truckergary]

Re: 1989 85hp force motor

it is a 17 foot spectrum boat unsure of the weight but the prop that is on it now is a 4x12.7x19 if this helps would appreciate advise

 

[roscoe]

Re: 1989 85hp force motor

There is a 12.- x 15p readily available for your motor, it should increase the rpm to about 4700. Also a 13p prop from Michigan Match.<br />I think it is available here in the iboats mall, not sure. Or try elsewhere if they don't have it here. Should be able to get one for $120-$145.<br /><br /><br />Those boats are well built, and fairly heavy, and for a number of reasons your motor will perform more like a 70hp, so 33-38 mph is all I would expect.

 

[DJ]

Re: 1989 85hp force motor

Also look at how deep the engine is sitting on the transom. The cavitation plate should be even, or slightly above the keel line, of the boat.<br /><br />I also feel it is way overpropped with a 19".

 

[truckergary]

Re: 1989 85hp force motor

want to thank all you guys for your help have put boat away for the winter turning cold here will try new prop in the spring thanks again for all suggestions