Originally Posted by
Cooter
This check will only be an effective diagnosis during your no-start condition. If the bike is currently running, it will pass all these tests.
All you need is 10 minutes, and test light that Harbor Freight will give you for FREE with a coupon.
1) If you have an extra spark plug laying around for any gas engine you can use it to test for spark, without removing yours at all. Plug your plug wire on it, ground the metal end and crank it. Check both plug wires. If you don't have a plug from your lawn mower, pull out one of yours and use it.
2) If you are getting spark at BOTH cylinders during this no-start condition you can stop looking for electronic reasons (except timing). Look for fueling issues. Does the pump run with the key/kill switch on?
3) If you are not getting spark at BOTH plugs, check the 3 wire plug going in to the coil. Thats the primary/ low voltage side. The wires on each end of the plug fire the coil when grounded. The center wire should be battery voltage. Check the wire on each side with a test light connected to the battery (+) and crank it over. You should get a blinking light on both. If you DO get blinking oil both, get a coil, yours is bad.
4) If you are not getting spark at ONE plug, swap the wires. If the spark changes cylinders, you need coil wires. If it does not, you need a coil.
5) If both wires do not blink, check the center wire of the CPS the same way, if it doesn't blink, and you have input voltage at the plug, get a CPS, yours is bad.
6) If the CPS wire blinks, check it at the ECM. NO blink, its the wire. Yes blink, its the ECM.
7) If you have a blinking wire on only ONE of the coil primary wires, check it at the ECM. NO blink, its the ECM. Yes blink, its the wire to the coil.
Once you finish ALL these very simple checks, IN ORDER, during a no start condition, you will know whats wrong with your bike without guessing and can fix it without spending money to replace parts that are good. 10 minutes. I'll wait.:angel: