63 Johnson 10hp loosing power

rick502

Cadet
Joined
Sep 2, 2012
Messages
6
I have a QD-24M that had been running well until Sunday. It started well but as I left the shore and accelerated it seemed to be running below full rpm. After 2-3 minutes it started loosing more RPM's. Within a couple minutes it was running at about what I'd normally see at half throttle. Only other symptom was it seemed to be running a little warmer than usual, though not overly hot. I stopped the engine for an hour or so and when I tried again it behaved the same, started ok but quickly lost

Same fuel in tank as last time I ran w/ no issues. I checked all linkages they are good, carb settings unchanged and plugs were clean and dry. Thinking lack of fuel which would explain lack of power? Any ideas where to go next?
 

bbstacker1

Petty Officer 2nd Class
Joined
Mar 7, 2010
Messages
163
Re: 63 Johnson 10hp loosing power

Have you checked your fire, sounds like you might be dropping a cylinder. If the coils are original they are almost assuredly in need of replacing.
 

rick502

Cadet
Joined
Sep 2, 2012
Messages
6
Re: 63 Johnson 10hp loosing power

Haven't checked ignition side, would that fit with losing power as motor warms up?
 

AEROCOOK

Master Chief Petty Officer
Joined
Jul 28, 2004
Messages
872
Re: 63 Johnson 10hp loosing power

Haven't checked ignition side, would that fit with losing power as motor warms up?
It certainly could. Try pulling the plug wires off one at a time while it's running, if you pull one of them and the motor continues to run the way it was (no loss of RPM) then you have an ignition problem.

X2 on bbstacker1's original ignition coil suggestion.
 
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