Logo

98 force 75 ignition question (s)

dtoole

Regular Contributor
hi, im working on a 98 75hp force. owner said that the motor wouldn't idle and would not restart.he also said that pushing the choke helped to keep it running some of the time. my first checks included compression (125 or so on all cylinders ).and a spark gap test.number 1 and 2 would jump 7/16. # 3 ,after i cleaned terminal on coil, would jump 3/8. so i went through the fuel system. new hoses,primer,fuel pump kit. it ran perfect in the drum for almost an hour. put it in the water and it had a definite miss. i then pulled the carb. every thing looked good. so i went back to the #3 cylinder . it would not jump a 7/16 gap. i swapped input wires and it followed the coil.so i replaced the coil with a new cdi. now the tach fluctuates and there is still a very slight random miss.(maybe a fouling plug ? ) one other note, in my haste to get it in the water for a test, i forgot to attach the feed wire to the coil.(STUPID MISTAKE) i ran the motor no more than 5 min then plugged the wire in. the tach started acting funny before i plugged the wire in.what did i hurt ? the stator? or the regulator ? any thoughts would be appreciated.......david
 
Sometimes the tach can affect the spark.
Unhook it and see if it makes a difference.
The carb air screw set right?
Start at 1 and 1/8th turn out.
 
David, does your model have the Prestolite ignition? Two blue "boxes" - one feeds cyl 1&2 the other one #3 (with the leftover side hooked to nothing?
 
97 doesn't have the blue/black Prestolite packs.
If it needs to be choked to keep running the carb low speed jet and air screw need o be cleaned or adjusted.
 
hi, thanks for the responses. as stated earlier i have corrected the stalling and shutting off problems. and i did go through the carb and found nothing wrong.my concern now is the fluctuating tach and the random misfire.i dont know how to paste a link to the ignition diagram. its a 98 75 hp force serial # oe321176 graham. thanks again.....david
 
jerry, i was reading in one of your other posts about grounding the spark plug wires while setting timing. if i ran this motor with the input wire connector disconnected on #3 cylinder,what would it have hurt?
 
Back
Top