1988 85hp force low rpm?????????

[bloodbought]

Hello i have a 85hp force on a 1988 bass trophy when running full throtal i can only get 4000 rpm cant get the boat faster then 29 mph and when i try to rev it up in nutral cant get above 2000 rpm thats with the throtal wide open thought the cable may be stretched or something i never worked on a boat motor all help is greatly appreciated thank you

 

[john from md]

Re: 1988 85hp force low rpm?????????

First you need to buy a Clymer Force Outboard Shop Manual or a Seloc Force Outboards 1984-1999 Repair Manual.

This can be many things but the initial symptoms tell me that one of your cylinders is not carrying its weight. The first thing you need to do is do a compression test and check for spark on all three cylinders and get back to us.

 

[bloodbought]

Re: 1988 85hp force low rpm?????????

will a automobile compression guage work and whats the best way to check unhook the plug wires so it dont fire???? this marine stuff is to costly to learn by mistakes so all help is needed thanks

 

[john from md]

Re: 1988 85hp force low rpm?????????

Take all three plugs out to make it easier for the engine to spin

If you have a kill switch, activate it to kill the ignition circuits. You can then spin the engine with the key. If you don't have a kill switch, then you must jumper the coil wire to ground. If you don't do this, feedback will ruin your CDI circuits.

It is not necessary to put the trottle in WOT position to do a compression test. It just complecates matters as then you have to jumper the neutral safety switch.

If you have an automobile solinoid jump switch, it will work on the boat just like it does on a car.

 

[bloodbought]

Re: 1988 85hp force low rpm?????????

call me stupid but how do you ground out the coil i just want to make sure i do it right

 

[john from md]

Re: 1988 85hp force low rpm?????????

You can either pull the kill switch which grounds the CDI modules or put a small jumper with an aligator clip on each coil high tension lead to ground. You can buy the small jumper wires at Radio Shack.