my sons 50cc wont start.no spark at the plug.changed cdi box and coil and still no fire.we need help.

 

Check the rear safety cut off switch. Mine did the same thing. After replacing the plug, coil and stator. and much time on the phone with a tech. I gave up on them and starting testing the wiring system. I cut the wires going to the walk behind safety and reconnected them (without the safety) sure enough it started right up. good luck!

 

thanks for the help.can you tell how to re-wire the rear kill switch im going to try noting esle has worked.

 

I seem to have the same problem, changed coil, cdi and no spark, could you please tell me exactly how you rewired it. I followed the wiring up to the ignition switch and did not understand exactly how it worked, Thanks Ken

 

Here ya go Donna:


TO BYPASS ALL CUTOFF SWITCHES ON KMX-50, KMX-110, RFX-110



LOCATE CDI

CUT BLACK WIRE WITH WHITE STRIPE CK. FOR SPARK LEAVING ENOUGH WIRE TO RECONNECT.

THIS WILL RULE OUT ALL CUTOFF SWITCHES ON THE ATV INCLUDING: IGNITION SWITCH, HANDLE BAR SWITCH, SIDE CUTOFF (KMX-50 ONLY) REAR CUTOFF( KMX-50 ONLY)



CDI 5 PIN PLUG WIRING DIAGRAM:



1. GREEN- GROUND
2. YELLOW W/BLACK- IGNITION COIL
3. BLACK W/ WHITE- IGNITION KILL
4. BLUE W/ WHITE- IGNITION PICK-UP COIL
5. RED W/BLACK ? STATOR COIL

Hope it helps, Jim

 

Thank you, I will try it Saturday. Donna

 

Tried those ideas and even took electrical parts off another 50cc that was running and still could not find the problem, any other ideas would be appreciated. thank you, ken

 

i tried cutting black-white to cdi and still no fire.i have changed kill switch on handle bar and nothing.things we changed---cdi,coil,fuse,switch on handle bar.if anyone has any idea please let me know we need help.

 

This is what I have changed and I know these parts are good because I took them off another 50 that was running. coil, cdi, rear safety switch, waist kill switch,fuse, changed ignition switch,changed plug and plug wire.don't seem to be getting any spark to the plug from plug wire but I did not get any from the good 50 either, I am getting spark from the stator just like on the good one but still can not get to start, getting a little disgusted. Ken

 

How are you checking for spark? You should be getting spark if the good 50 runs. Try this if you have a ohm meter, its a link to a trouble shooting page for no spark:

http://www.redcatmotors.com/nospark.asp


I'm afraid this is all the more I can help, sorry.