Help me please, I'm lost. No Spark

Roscoe · 07-16-2017, 10:44 AM

Diagnose, diagnose, diagnose. You need voltage from the stater to the CDI, this charges a capacitor in the CDI ... then you need a voltage signal from trigger coil which allows the charge in the capacitor to cause current in the primary of the coil which causes a spark at the spark plug. There are gobs of youtube videos that explain this better than I can. Watch a few and learn the theory of how the ignition system works then use a multi meter to determine if the proper voltages are what they need to be to produce a spark. Firing the parts cannon at a problem works but diagnosing and replacing what is needed is how you know you've fixed it properly.

DRyker · 07-16-2017, 11:03 AM

That's the thing. I've done all those tests and all the parts seem good.

DRyker · 07-23-2017, 08:30 PM

I ended up taking out all of the wiring and combing through every inch of it. Fixed a few issues, there were exposed positives and grounds in multiple places.

No shorts now, I've got around 170psi compression, getting good fuel, carb is clean, have good spark, valves are good, timing is good, starter motor is good. But it still. Won't. Start.

I've been out there all day and can't get it going. Does anybody have any ideas on what the issue could be?

sc00ter · 07-23-2017, 10:44 PM

This is going to sound crazy, but this is what happened to me before. I had a beloved moped with a V1 motor. Built it way back before the internet existed so help was not close by. Anyways, was riding it to work one morning and it just shut off. No warning of any type. Just stalled. Was getting fuel. Getting strong blue spark. Just would not start. Got it home and keep messing with it. No luck. So, I pulled the stator off just to check. Turns out the 2 screws that held it in place broke and the stator flipped a perfect 180 degrees upside down! If I never removed it I never would have figured it out. One of the screws took a chunk of the case with it and I ended up selling it for parts. We bought a Carter Brothers go cart for my wifes nephew one Xmass. The adults rode it and burned the clutch up and expected ME to come and fix it!? Needless to say its been sitting so long now its only good for scrap metal. My guess is timing related.

07-16-2017, 11:03 AM	#2
DRyker Join Date: Jul 2017 Posts: 5	That's the thing. I've done all those tests and all the parts seem good.
	0

07-23-2017, 10:44 PM	#4
sc00ter Join Date: May 2017 Location: Norfolk, VA Posts: 531	This is going to sound crazy, but this is what happened to me before. I had a beloved moped with a V1 motor. Built it way back before the internet existed so help was not close by. Anyways, was riding it to work one morning and it just shut off. No warning of any type. Just stalled. Was getting fuel. Getting strong blue spark. Just would not start. Got it home and keep messing with it. No luck. So, I pulled the stator off just to check. Turns out the 2 screws that held it in place broke and the stator flipped a perfect 180 degrees upside down! If I never removed it I never would have figured it out. One of the screws took a chunk of the case with it and I ended up selling it for parts. We bought a Carter Brothers go cart for my wifes nephew one Xmass. The adults rode it and burned the clutch up and expected ME to come and fix it!? Needless to say its been sitting so long now its only good for scrap metal. My guess is timing related.
	0