1985 Merc 115 "Tower of Power" only has spark on one cylinder

sth5591

Cadet
Joined
Jul 16, 2016
Messages
9
I recently acquired a 1985 Merc 115 to replace my old, dead 70hp Johnson. The motor had been sitting for at least 12 years, but looked very clean, it wasn't even dirty or greasy, and it had the original spark plugs in it. I rebuilt the carbs and replaced every fuel line and the spark plugs and got it ready to test fire. Upon trying it out I am only getting spark to cylinder number 1. I noticed a few cracked/dry rotted wires by the rectifier and switch boxes and replaced them and tried again. Now I am just getting BETTER spark to cylinder number 1. If I switch the wire going to the #1 coil to a different coil I will get spark on that cylinder.

Edit: And yes, the impeller will be the next thing I replace.
 
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sth5591

Cadet
Joined
Jul 16, 2016
Messages
9
Bump...I'm just looking for some advice on where to start testing the ignition system?
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
36,033
Some will argue and cast doubt.--------I would start with inspection of the starter / battery / battery cables.---Slow cranking means spark issues.
 
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