Hi, I'm new to the forum but used this site extensively to solve a problem a friend had with his bike so I thought I should at least share a little problem solver I discovered.
He bought the bike knowing there was no spark. He replaced the stator and primary coil also known as pulser coil or exciter coil or rotational etc., as well as the CDI, secondary coil (the one attached to the spark plug wire) along with the wire and plug. Still no spark.
He dropped it off at my place a month ago to see if I could figure out what was wrong. I did all the recommended tests and everything was within specs. I checked all connections and switches, all okay. So everything was perfect but still no spark.
Here's the problem solver, I devised my own test and pushed "Bell wire" beside the positive and negative pins of the primary coil inside the plug of the ATV wiring harness (see below for wire identification) leading to the CDI box. I touched the wires to the ends of a "Double A" battery observing polarity. The spark plug sparked. So I knew right away everything in the ignition wiring was good and there was a problem with the primary coil. So there you go, no ohms and crap to test, you'll know right away where to look for the problem.
I pulled the stator housing and found that the primary coil (or what ever you might call it) was mounted upside down, I removed it, turned it over, remounted it and now the machine runs perfectly.
Here is some info I could not find on line regarding the primary coil:
The after market stator on this machine:
Blue with yellow stripe is positive from the primary coil
Green with white stripe is negative from the primary coil.
ATV wiring harness:
White with blue stripe is positive from the primary coil pin to CDI.
White with red stripe is negative from the primary coil pin to CDI.
I hope this information helps somebody.