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1974 25HP Johnson no spark

F

FlyinHigh

New member
I've replaced starter, starter solenoid and coil packs but still no spark. Only other thing I can think of is magneto but I can't get flywheel off to check it. Ideas?
 
Hah! Went to a website and determined that my model is a 76 not 74 which has no magneto, but has contact points and breaker and condenser. Called local boat shop and got an appointment to get the flywheel taken off not sure if they’ll charge me or not. Also bought a tuneup kit for the motor.
 
There is no “part” called magneto, that is the term to describe the system that generates voltage to the spark plugs.
Look again at the parts diagrams here. Every single model of 1974, 25HP Johnson shows a live link labelled MAGNETO.
Click that & it will open the system in full.
 
My bad…it’s a 76 not a 74. On the 74 parts diagram there was a “magneto” label on a couple parts. On the 76 there was no such label. Look, I don’t care if we call it an elephant….I just want to generate spark. I’m replacing condensers and points. Any tips to setting the points?
 
It’s all there. Under 1976, select 25 hp, then select the model that matches yours. That opens a menu of every system on that motor, they are listed alphabetically, so, MAGNETO is down near the bottom.
I don’t have a 25HP, but most motors have the flywheel embossed - “set points .020”. This is with the cam centered on the points rub block.
Do a search, there are more accurate/easier ways, using a multimeter to set them, (the points when closed ground out the ignition, hence sparkplug fires when the points open),
It’s easier to watch a video than typing the procedure.
 
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