1971 Mercury 9.8 110 no spark mid throttle

[bassindan]

spark at low and high throttle but not mid throttle. HELP!

 

[bassindan]

Re: 1971 Mercury 9.8 110 no spark mid throttle

No one? Really tired of this motor.

 

[MH Hawker]

Re: 1971 Mercury 9.8 110 no spark mid throttle

I dont know much about that motor the one I have is a 96 and CDI ignition. How ever it dose have a 2 step ignition system that crosses over to a higher voltage around 2500 RPMs. But i dont think your has that.

 

[Oldcraneguy]

Re: 1971 Mercury 9.8 110 no spark mid throttle

I had the same problem with my 69 9.8, turned out to have one bad charging coil on the stator and I think the 71s used the same stator.
If it looks like this one or has a part# 336-3996*** you might have the same problem...cheapest one Ive found was $235 on ebay.
I could spin mine with a drill with the plugs out and watch the spark go from bright blue to zip as I retarded the throttle back to the "shift" position. Also make sure to replace the insulator blocks on the maker points as well as these are hi-voltage and will arch to ground easily....good luck...ocg

CDI Mercury Stator 2 Cylinder 174 3996 | eBay

P.S. never use the kill button without the motor in the water, use the choke when dry or on ear muffs

 

[Geff Gordon]

I have a 1971 9.8. Ran great at high speed but died at the same speed predictably on deceleration. With cowling off, I repeated the rev-decelerate-die, until I noticed that tapping sound, indicative of an high voltage leak. One of the high voltage wires that ran around the engine under the flywheel had worn through and would short out when the deceleration caused the mechanism to move to just the right location. Get your engine to run, and listen when the engine stops firing.

 

[GA_Boater]

I have a 1971 9.8. Ran great at high speed but died at the same speed predictably on deceleration. With cowling off, I repeated the rev-decelerate-die, until I noticed that tapping sound, indicative of an high voltage leak. One of the high voltage wires that ran around the engine under the flywheel had worn through and would short out when the deceleration caused the mechanism to move to just the right location. Get your engine to run, and listen when the engine stops firing.

You're answering a question that's over 1 1/2 years old. Please read the Help Tip on top of the page about replying to old threads.. Thanks

Closed