1985 force 85hp outboard running problems.

Hello i have an 85 hp force its old but never let me down. will idle like a cylinder is missing. and wont plane and then it will run great for a little bit then run rough again. all in the same outing. then it will run perfect at times. compression was 127 119 and 124. if it was the low compression would it cause all the different running variations? and i did the compression test when cold. all 3 plugs get fouled up at one outing. swapped out an ignition coil on the middle low compression one. should i bother doing a fuel pump rebuild and the three carbs? or is the compression variance off to much? thanks for any suggestions. i also put in a marine carb cleaner around 10 tanks ago. and was using a new oil 50 to one as usual.

Does the primer bulb go hard ??----I would suggest an ignition test.------Check what the system can produce.------Good spark will jump a gap of 3/8" ( 1 cm ) or more.----It will snap when it is good spark.----Or run with a timing light and observe spark during operation on each lead.------Or use a strong flashlight and observe fuel coming up the main nozzle on the 3 carburetors.----No money spent doing some simple testing.

Possible? the trigger wires are shorting out?
The wires are very thin and brake easily, check
for broken wires under the shrink wrap.

Jerryjerry05 said:

Possible? the trigger wires are shorting out?
The wires are very thin and brake easily, check
for broken wires under the shrink wrap.

Click to expand...

Will do as soon as the weather breaks.going to take the ignition coils off and bring them in to test the ohms. Do t want to move wires around when below freezing. Thanks