2006 Big Bear 400 has an intermittent ignition problem. Half a dozen times over the last few years, it has refused to start. Let it sit for a day, and it has always self corrected. On one occasion, I was able to determine that there was no spark before it decided to work. On this last occasion however, letting it sit for a day did not resolve the issue. I had a day and 1/2 to troubleshoot it before it decided to work again.

Coil Primary to ground - 0.6 ohms
High Tension lead to ground - 10,300 ohms
High Tension with cap resistor removed - 5,040 ohms
Pick-up coil - less than 1 volt AC
CDI output to coil - 2 volts AC
Volts to CDI Unit with key on - 12 DC dropping to 11.5 when cranking
Proper CDI and coil ground connection confirmed

I could hold onto the High Tension lead, and received only an initial mild shock. Further cranking produced no more shocks.

After I had decided that the low output from the CDI unit indicated it was maybe the problem, it suddenly started to work. Using pins pushed into the wires, I measured the voltages again. The pick-up coil voltage was the same, but the input to the coil measured 10 - 12 volts AC with a digital meter. The CDI unit is relatively expensive to replace on a hunch, so I am seeking advice from someone who may have experienced a similar problem. Can a CDI unit fail like this?

Thanks
J.A. Coutts

 

I recollected that the problem never surfaced in the winter time. It failed again, so I removed the CDI unit and threw it in the freezer for an hour. When I plugged it back in, the engine fired up first try. While it was running, as I was bolting the CDI unit down, I dropped it about 1/2 an inch onto the frame. The engine died immediately and would not fire up again. That more or less verified that the CDI unit was faulty and a new one has been installed. J.A. Coutts