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Mercury 110 9.8 late 70s? No spark.

R

Rjybilcom

Member
I bought this motor a month ago. First two weeks it started up with a few pulls of the rope and ran like a champ. Once it was warmed up, it would crank on the firstly pull. The weekend after, the pull rope broke. Couldn't put a rope on myself, took to a boat shop. Guy shows me where the top plate looked like it had a spot weld on the top plate and bolt. I guess he gave up on it, so I bought a used one on Ebay. Pull rope spins the flywheel just like before, but I have no spark on either plug using a tester. Had to take the coils off either side of the starter assembly and now no spark. Stator should still be good as it was running before. Do I not have the coils properly grounded? Or is the switch box bad?
 
That makes it 1980 vintage, since replacing the starter has nothing to do with loss of ignition. Check for any signs of dry rotted, broken wiring. These engines had notoriously poor wiring that degraded over time, and didn't like being disturbed check every wire, starting with the kill switch and move on to grounds, trigger and switchbox wiring.
 
Doubt you had 2 coils fail at the same time.----So test the components under the flywheel.-----If they are good then yes the switch box might might be the culprit.----But I am not saying to rush out and get a new one.-----That process / decision is up to you.
 
I noticed a wire from the killswitch has a frayed wire. Not the one to ground. I was to hit it with some solder tonight. Testing for continuity from that post of the switch to ground is OL until you press the switch, then you hear tone. Is this how it's supposed to be?
 
All I can suggest is to test the circuits with a DVA meter. You can buy an attachment to a regular ohm meter on Amazon for about 30 bucks.

Jeff
 
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