87 Force 9.9 Intermittant Miss Fixed!!

hankll

Petty Officer 1st Class
Joined
Sep 10, 2006
Messages
224
I revived this motor,which I was told only had pull start spring problems, which I was able to do "special engineering" and got that fixed. I cleaned out the carb, but it didn't have any major issues, other than some fine particles in the carb bowl. Then I had a miss that I could not pin down. I replaced the condensers, polished the points, put new plugs in, and replaced kill switch wiring (someone installed lamp cord wire) and still I had a miss, yet it showed spark when I cranked to test. I was seeing spark so thought coils were ok. Finally after the 4th time with the flywheel off, I did a more thorough coil test. I took the connections off the points and then tested, for primary resistance and secondary resistance - JACKPOT - lower cyl coil wasn't showing any resistance in the secondary to the plug. Then I pulled the boot off to prepare to take coil off and then decided to test the coil again and pushed the probe into the end of the spark wire and I had resistance in the spec range listed in the manual!!! It was the wire conductor broken where the spark plug clip connector was pushed through the insulation and through the wire. That almost made me pay for a new coil, and cheapest was $66.00 to as high as $111.00, that was gonna be a heavy hit on the wallet. But, now, it sure does run sweet !!! I'll remember that one next time I'm having a hard to pin down miss.
 

john from md

Commander
Joined
Apr 13, 2008
Messages
2,184
Re: 87 Force 9.9 Intermittant Miss Fixed!!

Good job! Just a note about points. You say you polished them but I don't know what that means when applied to points. I would caution you not to clean them with emory cloth or any other abrasive as they are coated to keep deposits from forming. If you cut through this coating, you will start to get build up on the points.

John
 
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