91 Force 70HP

chaddizzle29

Recruit
Joined
Oct 1, 2013
Messages
2
hi

i replaced the stator with a new aftermarket 9 amp no spark, put in new plugs...still no spark, replaced switchbox still no spark all thats left is the vr/rectifier although when i put in a conventional plug i get spark i dont get it any ideas guys?
 

pnwboat

Rear Admiral
Joined
Oct 8, 2007
Messages
4,251
Re: 91 Force 70HP

I assume you have checked the magnets under the flywheel? If any are cracked, partially missing or completely missing you'll get weak spark. To see if the regulator is the cause, just temporarily disconnect the stator wires that go to it and see if that solves your problem.
 

Frank Acampora

Supreme Mariner
Joined
Jan 19, 2007
Messages
12,004
Re: 91 Force 70HP

It takes much less voltage to fire a conventional spark plug than it does to fire a surface gap plug. If you can fire a conventional bent electrode plug, the CD unit is functioning as is the stator.

NOW: CD is capacitor discharge. The stator charges capacitors inside the CD box and the trigger signals a transistor to dump this voltage into the coils. SO: If the capacitors are not charging fully, the coils will not produce the correct high voltage to fire a surface gap plug.

Thus, check the resistance of the capacitor charging windings on the replacement stator or if you have the correct meter, check to see if it delivers about 250 volts.

Check the coils for resistance on both the primary and secondary windings and check to see that the coils have good grounds. Check to see that the ground wire to the electronics mounting plate is present and not broken. In fact, it would be good practice to "daisy-chain a ground from each CD box and each coil to the ground terminal on the engine terminal board.

And oh, yeah--as stated above, weak flywheel magnets will prevent the stator from delivering full voltage.
 
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