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Discussion Starter #1
My 1998 Polaris magnum 425 recently lost spark. I was out riding when it bogged down and shut off. I let it cool down for a bit and then went to start it and the battery was dead. Tried pull starting it and the rope broke. Towed it home and let it sit for a couple days.

Took the recoil apart took broke. Parts out and put the charger on it and tried starting with no luck. Pulled the plug and no spark. Not sure where to check for problems. Any help please???
 

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Is the Kill switch on?
 

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I have a 1995 Polaris Magnum 425, I've found two issues that were likely the culprits, the first issue was the Pick-up coil on the flywheel was bad and the second time I lost spark I found it to be the CDI box which controls the spark went bad. I had a very hard time finding a CDI box that would work, I wasn't sure that the Stator was still good and
they are not cheap and being they are an electronic part they are not returnable. The best thing I ever did was eliminate the CDI box and the Stator by switching the ignition system from AC to DC. It's not that expensive and will eliminate problems down the road. There's a great video to show you how to convert this for the Polaris ATV. RMstator.com If you have battery power you will have spark providing the pick-up coil is good and that's actually easy to test. Good Luck
 

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Discussion Starter #6
I tested resistance on the stator and found a short to ground. Will that cause no spark as I thought it was just for charging the battery. The pick up coil and everything else seemed to check good
 

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The stator does two things - generate AC voltage to charge the battery and AC voltage to charge (excite) the CDI - if you checked the charging wires (yel, yel/red and yel/brn) and there is continuity to ground, it will not charge the battery - if you checked the exciter winding (red, blk/red and green) and it is shorted to ground, then no spark - if you checked the pulse coil (wht to wht/red) then no spark. If you unplug the black wire at the CDI unit and get spark, then the ignition system is working and you have a short in the kill wire.
 

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Discussion Starter #8
It was the green wire going to exciter coil grounding out
The stator does two things - generate AC voltage to charge the battery and AC voltage to charge (excite) the CDI - if you checked the charging wires (yel, yel/red and yel/brn) and there is continuity to ground, it will not charge the battery - if you checked the exciter winding (red, blk/red and green) and it is shorted to ground, then no spark - if you checked the pulse coil (wht to wht/red) then no spark. If you unplug the black wire at the CDI unit and get spark, then the ignition system is working and you have a short in the kill wire.
it was the green wire from exciter coil. Shorting to ground. Unplugging black wire does nothing for spark. Does that explain the bogging down before killing?
 

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If the green wire was slowly shorting to ground, the output would fall and the spark would weaken until it reached a point where it lost spark altogether - the green wire is a center tap for the exciter coil - important to the CDI unit - other models do not have the center tap and a different CDI unit, but they are 100% interchangeable - you can change from a 2 wire CDI to a 3 wire and vice versa, but you have to have the right CDI box to match.
 

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Discussion Starter #10
Ok I ordered a new stator hopefully that brings the spark back. I also found the red wire is broken coming from the regulator/rectifier. That could explain the charging issues I’ve had in the past.
 
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