I have looked through this forum trying to figure out why my 2005 KFX 400 wont start.

I have rebuilt the carb, checked valve clearance, checked spark and fuel.

I am wondering if the CDI is failing or faulty. The bike ran just fine in the fall when I put it up for the winter.

Having looked through the service manual, I cant find how to test the CDI. Can anyone provide assistance so I can either confirm or rule this out as being the problem.

Thanks.

 

Remove the spark plug from engine. And then reconnect the spark plug to the plug cap/wire. Place the electrode end of the plug about 1/8" away from the engine block and have your lil brother crank the engine. Do this in a dark area. If you see blue arcing (voltage jumping) between the spark plug elecrode and the engine, your CDI is good.