99 Yamaha Grizzly 600
Had no spark. We changed the stator with one purchased from Ricky Stator. It ran fine about 4 hours while snow plowing and it died again. Again, no spark. We changed out the CDI box, ignition coil, new plug. We have a Yamaha service manual and checked everything, resistance on factory specs and also the ones for stator and pickup provided by Ricky Stator. Everything checks out fine. We cleaned the grounds and untaped the wiring harness and checked the ground crimps on the harness. We also did a point by point amp test by putting 2.5 amps through each wire to check for corrosion and broken strands. All that checked out fine. The source coil is putting out 91 volts. The pickup is fluctuating when cranking between 2 and 4 millivolts. I do not how many amps the source coil is actually putting out. I also put a inductive timing light around the feed wire to the ignition coil and when you are cranking it does not flash. But, when you let off it flashes once or maybe twice. Also if you crank it with the electric start, the timing light will flash once the battery is drawn down the point that it will barely crank. I have taken the kill switch apart and checked the contacts. I ohmed it and checked voltage. Also the main switch checks out fine. I'm out of ideas! Please help!

 

sounds like a new battery is needed. as for the "no spark"...hmmmm?

you checked a lot of things. i was going to suggest the kill switch and ignition switch but you've already done that.

do you think the sarter may be at fault?

 

its a slim chance, but there may be moisture in the plug boot.. dielectric grease on every connection would be a good idea... and new battery sounds good too

 

Battery seems good, from what we can tell no damage or moisture to spark plug boot. We don't get spark either with electric starting or with pull starting. (well, there is a weak spark seen with the induction timing light and it seems to happen after we let off the starter button) Does that help?