I have a 2004 Polaris atp 330 that doesn't have spark. I've already checked the stator and trigger coil resistance and they are ok. I've disconnected the black wire to the cdi to bypass the switches. The cdi is getting 12volts to it.

This is what seems strange to me - The voltage of the primary lead wire going from the cdi to the coil is reading 12volts dc at rest. Shouldn't it read 0 volts? When I crank the electric starter, the voltage drops to 9 volts dc. Does that sound like to cdi is bad?

 

This is a dc/cdi ignition,should have voltage at the cdi from the battery. Check cdi peak voltage,between the yellow/blue cdi wire and ground during cranking with spark plug in,plug cap attached. Should be around 20 vdc.If less then possible cdi problem. Also check resistance on coil. Coil tab to ground .03 ohms,coil tab to plug wire (cap installed) 11.3k ohms.Cap removed,coil tab to wire 6.3k ohms. Cap itself is a 5k ohm resistor cap. Should read around 4.87k ohms on average. Replace coil if out of range.

 

Thanks for the advice. The cdi peak voltage is reading 10 volts so I think that is the problem.

Question: When I checked the pulse trigger coil, it was 456 ohms which is within spec. Is there another way to check it to be sure its good?

 

Manual I have says pulse coil should be around 520 ohms,but you're within + or - 20% range. This is all the manual says on testing on the 330. What you can do is make sure you have no more than .030 air gap between the coil and flywheel. If it does you can "lightly" tap the coil bracket inward,then check for spark.If it doesn't help,then the cdi could be the problem.Plus you can pull the black(kill wire) from the cdi and see if it has spark. Not uncommon for the internal kill circuit of the cdi to short out.I've had to replace cdis because of this.

 

It ended up being the cdi. I picked up a used one and it works good. thanks for the help.

 

Glad you tracked down the problem.