I'm running an MSD 4217 single cylinder. The coil is a MSD 8204. I'm running B9egv plugs. MSD 8.5 wires. Ignition is on 10amp fuse. Running 18v battery.

It ran fine for a couple months. So we took a 6hr trip to run this bike. Ran fan friday night. On Saturday, it saws a different story.

It would idle fine. But ad soon as the motor would rev up it would lose spark and then kick back in. Backfire out the pipe. Then the ignition died. Tested the coil. Ohms checked on the coil at 1.0. Power was going into the 4217 box. Power checked good at the pickup. When I ohm'd out the pickup it was at 9. I checked and installed a new on and it read 0. The LED went out on the box to show it was sensing a signal at the pickup.

Do I need to run a resistor plug with this ignition?
Would vibration make the box go out?
What's the max voltage? (18v should not be too much?
(There another guy with the same set up I have and his has ran for over two years)

You guys really need to include some trouble shooting in the directions of the 4217. Spending 5 hours on a Saturday at the races and not knowing the specs on a box is not what I call a fun weekend.

Please get back with me.