This is my brother's ATV. It cranks, has fuel, but no fire. He suspects the CDI. Is there a way to back probe this thing and trouble shoot it? Any suggestions other than the CDI? The coil tests fine.

 

This sounds dumb,but have you tried a new plug? My Wolverine was starting hard and hesitating, pulled the plug,the electrode was pretty worn, found a used one, put it in,and it fired up and idled like new ! also check all connections and make sure the line fuse is good, before putting any parts like a CDI in. Hope this helps you out.

 

pull the plug and ground it on the motor, turn it over and you should get spark. If not you will have to look at the plug wire and trace it back. The CDI puts out 12v to the coil, when it switches to ground the magnetic field collapses and creates the 20 some odd thousand volts to light the plug. If you have a very fast meter you can meter the coil wire from the cdi (usually orange on yammies).

 

Does the Engine have good compression as well? IF not a new top end should be instore. But I would agree with the others, check the spark.

Will the wolf do anything, like caugh, spit???