Hello; I've got a Avanti 110 cc, that has no spark.
I tested the ignition power pin while spinning over, I got 72 volts ac.
I tested the timing trigger pin while spinning over, I got between 197-269 ac
I tested the ignition power pin for resistance i got 414 ohms
I tested the timing trigger pin for resistance i got 122 ohms
I tested the ground for resistance i got .2 ohms
I tested the ignition coil pin for resistance I got .5
I don't understand why it measures so high on the timing trigger pin
I'm using a fluke 787 meter that auto ranges.
Hopefully someone can help walk me through this, Thanks a million!
Marty
Also I have the common 5 pin ac cdi box and have already disconnected the kill switch wire from cdi

 

Wow. That Fluke 787 is one fancy meter. You borrowed this from work, right? Keep care of it. Replacing it may cost more than your quad did brand new...

I don't believe your timing trigger pin has 269 volts AC on it. I would believe that you might have 269 millivolts AC on it. That is the same as 0.269 volts AC. That is in the ball park for a good trigger voltage. You probably want to check this again - especially since your meter is autoranging. It may gear way down to the millivolt range without you noticing in order to see really small voltages. Most meters out there won't measure really low voltages with this much resolution, but like I said you have a really fancy meter.

All your other measurements sound reasonable.

With the kill switch wire still disconnected, measure the voltage to the coil on the AC voltage setting while cranking the starter. What do you see? Your meter is different than most meters in that it measures true RMS voltage. I don't have a meter that does this, so I curious about what a fancy meter will read. In any case if your CDI is being triggered you should see something here. Cheap meters like mine read mostly zero volt readings with random numbers in between reaching up to 100 volts or so. If you see zero volts all the time then the CDI isn't being triggered. That would be a clue that the CDI is bad as long as your trigger voltage is at 0.20 to 0.50 volts AC.

 

I'm going out to try it right now, let you know how it turns out

 

I tried it out, I'm getting 20 vac to 24 vac consistantly. It never shows 0, it goes 20 21 23 22 24 and starts over very fast. Not exactly in that order everytime.

 

So are we agreement that the trigger voltage is reading 200 millivolts or so (0.200 volts - not 200 volts)? Or is there still some discrepancy here?

24 volts AC on the output to the coil sounds way too high to me for a true RMS voltage reading, but this is actually a way complicated subject and probably off topic to this discussion. Maybe this voltage is OK. The point is that you are getting something at the input to the coil which indicates that the CDI is being triggered. If your weren't getting a trigger signal and the CDI wasn't working then you would read zero voltage here.

Just so we could tie some loose ends and see if we live in the same universe, is there any way you could come up with a lessor, more common meter that us mere mortals can afford ? I'd like to see if what you are seeing is the same as what others see when using cheap meters on cheap chinese quads .

If you are getting output from the CDI to the coil and you are not getting spark then it has to be the coil or the spark plug.

 

Thanks Lynn

 

I'm having an issue with no spark on my 150 Chinese BMX. I understand that I need to check my AC voltage on my CDI. I know which pin but how exactly do I do this? Where do I put both leads of the meter?

I can turn the meter to AC I'm just not sure where to put the ground lead, thanks.

 

Hope this helps

 

Thanks. I found my problem. My kill switch was grounding out. Took me all afternoon to figure it out, lol.

 

I ordered a new coil, and it fired right up! Thanks for your help