2002 Yamaha Beartracker 250 has no fire

[Lamar1743]

2002 Yamaha Beartracker 250. I get .19vac into the coil but nothing at the plug. There is no spark. It was running fine, and then I didn't start it for 2 months and this is what I'm faced with. I keep it in a shop and out of the weather.

What voltage should I read input to the coil and output to the plug?

I ordered a full service manual yesterday, but thought someone on here might have some experience. Thanks

[DirtDemon]

You won't get any voltage at the coil wire unless the CDI is making it fire. Typical coil output to the spark plug is like 40,000 volts. I don't think that there is really any voltage coils primary terminal either, unless the CDI is firing. As I understand it, the CDI takes the 12v input and coverts it to around 600v AC using an internal inverter. When the CDI gets the trigger signal from the pickup coil, the internal capacitor discharges the 600v charge to the primary terminal on the coil. The coil turns that 600v into the 40,000 volts needed to jump the spark plug gap with a strong enough spark to ignite the air/fuel mix in the combustion chamber. I would recommend testing the voltage at the coil's primary terminal while someone is turning the motor over for you. You should get a better reading that way. If the voltage is several hundred volts or shows a relatively high, fluctuating reading, then your problem is likely the coil. If the voltage is low and, I would suspect the CDI is the problem, if there is none, or next to none and doesn't fluctuate, I would say the pickup coil is bad. I think the best thing to do though is wait for that manual, because I am generalizing, and your quad may use a slightly different style of ignition. Also, the repair manual will have some directions and specs for some direct resistance tests to test some of your ignition components. One thing I would recommend is inspecting for loose connections, bad/corroded grounds, or wires with worn insulation.

Good luck and welcome to the forum.

[Lamar1743]

Josh: Thanks for your well thought out reply. That helps a lot and I will let you and everyone know when I finally find the culprit.

[Sc0tt]

Another good idea is to check your wiring and the switch. I went round and round with Polaris everyone telling me it was the stator and wanting me to pay for a new one and come to find out it was just a loose wire/bad contact.