Bayou 400 no spark issue

[Michael P]

 Hi i have bayou 400 when i turn it over i get one little spark and that's it? New cdi ,switch, and a used regulator/retifier,new battery any suggestions would be greatly appreciated

[wanrep]

I've had 3 atv's in the shop with the "1 spark" problem.  2 of them were regulator/rectifier.  The other was a loose ground cable.  To check the ground, I take a pair of jumper cables and attach both clamps on one end to battery neg. and the clamps on the other end to the motor and frame.

[Ajmboy]

Good information from @wanrep.  I would also check for loose grounds first.

[Michael P]

thanks i will check grounds when i get off work didn't think about grounds makes sense

[Kaj Colum]

I have a similar issue, but intermittant, guess I[ll be checking the ground as well.

[DLB]

I checked everything you could check and everything checked out so I replaced my CDI and still nothing. After a week of going over the atv I looked at the plugins on the old and new CDI. They were exactly the same except the pin placement in the connector from the pickup coil was slightly different so the connectors fit together perfectly but the pins were not making contact. I hooked up jumpers from connector to connector and had spark.  Swopped out connector ends and bike runs perfect. MAKE SURE YOUR PICKUP COIL CONNECTORS MATE UP!