1987 Force 85hp with intermitten power loss and stall

[petervann]

Very strange intermittent problem. At idle or just a little above idle, motor looses power and stalls. If I give it full throttle, it will then pick right up and go. Doesn't happen all the time, and there does not seem to be a common denominator as to when it does. I replaced the plugs, stator and power packs. Anyone have any ideas what else it could be? My mechanic seems to think it is electrical, but so far and $1100.00 later the problem is still there. Could it be a fuel pump issue or maybe a coil?

 

[roscoe]

Re: 1987 Force 85hp with intermitten power loss and stall

Welcome to iboats peter.

I would suggest richening the idle mixture screw, 1/4 turn out, on each carburetor. This will help determine if it is a carb/fuel related problem.

Doubt that it is a fuel pump problem, but it could be leaking to the inside of the crankcase, and flooding out the engine, causing it to stall.

 

[Matthew A.]

Re: 1987 Force 85hp with intermitten power loss and stall

There was a time my Force would do very much the same as you describe. Mine turned out to be a loose hose clamp at the fuel bulb. I would check the fuel system first since it's easiest. Look for loose clamps, [especially at the carbs] cracks in the hoses or a loose fuel pump bolt or torn fuel pump diaphram.
If fuel lines check out, I would then check the rectifier for shorted or blown diodes. Be sure to check the wire connections at the rectifier also. You can try disconnecting the rectifier. If the problem goes away replace the rectifier. Another place to look into would be to trouble shoot the stator and it's wiring as well. However, even though a stator pasts the resistance tests it could still be bad.
I would also check the wiring for the powerpacks as well as the terminal strip for the wires coming from the trigger harness.
Might also be shorted spark plug or plugs. It might be getting shorted via the spark plug boot and insulator causing a path to ground.

 

[Frank Acampora]

Re: 1987 Force 85hp with intermitten power loss and stall

Since it picks right up when you advance the throttle, it Could be something as simple as timing too retarded at idle. Check to see if the idle timing is 0 deg plus or minus 2. Also check to see if the idle RPM is 700 in forward gear. If the idle is too low, and the engine loads up a little on fuel, Like when you are idling to dock, it will tend to stall. Goosing the throttle clears it out and it picks right up.

 

[jason32038]

Re: 1987 Force 85hp with intermitten power loss and stall

On my 1986 85hp force there is a metal rod with a plastic round piece on each end on the throttle linkage. Try to loosen the 2 small nuts and extend the shaft to slightly push the throttle open more. Remember to retighten the nuts. This will also prevent the engine from dying when shifting into gear.