No spark on 110cc mini atv

[l00ker]

Kill switch is fine. Took it apart and found no problems.
I am measuring .1 volts AC on the timing trigger
I am now measuring 55 volts AC on the ignition power pin (I am assuming it is dropping due to battery going low)
I am measuring 120 ohms resistance on the trigger pin to ground
I am measuring 1 ohms on the ignition coil primary pin to ground.

Still no spark and have no idea where to go next ......

I have already tried 2 CDIs (new) .... could both be bad??

[waynev]

OK, only 1 more thing i can think of, does the quad have one of those remote start/stops on it?, maybe the alarm is armed and not allowing any spark.

[l00ker]

No alarm / remote kill.

[waynev]

Do you know what kind of quad you have other than "USED".

[l00ker]

I do not know the specific model. It is identical to the Roketa, Tao-Tao, or the Gio mini 110cc. They are all the same.

[TurboT]

Frustrating stuff.. I hate being a parts changer, but what about the ignition wire/spark plug wire itself..

You mention you changed the coil, but did you put a new spark plug wire on as well?

It sounds as if you have power/signal everywhere but to the plug, and it is the delivery method, and a cheap part to throw on.

I'll also let Lynn Edwards review your data too for more thoughts.

There is also a little part, jammed up under the body kit, I believe on the left hand side (If sitting on the quad). It's called the rectifier and has a four pin plug in it. Have you checked the wiring here? I had a 110cc Mini Hummer not sparking and this was the culprit, one of the wires was slightly pulled back out of the white connector, almost didn't notice it but it was just not quite making contact inside. The way it was wired and set, there was some pressure moving away from the plug, causing the wires to want to pull back. I had to shove them all in again and tape the wires to the frame to keep them from moving back. It's run ever since.

[waynev]

That sounds like it might be something worth looking at T, here's a pic of the wiring diagram from my gio 50cc and as T mentioned there is a wire going from the recifier to the CDI box.

[l00ker]

Thanks for the input. The rectifier is the ONLY thing that I have not looked at. Yes, When I put the new coil on it came with all new wires including the plug wire. I will look at the rectifier tomorrow.
Thanks for all of the input!

[TurboT]

Keep us posted!

[LynnEdwards]

Originally Posted by l00ker

Kill switch is fine. Took it apart and found no problems.
I am measuring .1 volts AC on the timing trigger
I am now measuring 55 volts AC on the ignition power pin (I am assuming it is dropping due to battery going low)
I am measuring 120 ohms resistance on the trigger pin to ground
I am measuring 1 ohms on the ignition coil primary pin to ground.

Still no spark and have no idea where to go next ......

I have already tried 2 CDIs (new) .... could both be bad??

The AC Ignition power output voltage is directly proportional to engine speed, so a lower charged battery (and associated lower cranking speeds) will cause lower output voltage. 55 AC volts is still good enough to power the CDI.

The only thing that looks abnormal to me is the 0.1 volt trigger voltage. It's low, but is it just your meter or a real problem? I don't know the answer to this. I use an oscilloscope to measure this voltage, but most don't have access to one of these

If you're ambitious you could make this:



One lead goes to the trigger pin, the other to ground (polarity doesn't matter).

The two back to back LED's will both flash when hooked to a working quad trigger pin. One LED flashes on the negative pulse, the other flashes on the positive pulse. You really could use any LED. The green ones don't conduct until they get 2.5 volts or so across them. Red LED's are around 1.8 volts. What this circuit does is prove that the trigger pin produces enough voltage to fire the CDI. At cranking speeds both LED's should blink at 10 times per second.

Also, there 's been a lot of talk about kill switches. Normally measuring the kill switch pin resistance to ground is sufficient to rule out these types of problems, but I was thinking that maybe there might be a problem with corrosion across one or more of the kill switch connections. Corroded contacts can be very nonlinear - they might look open for low voltages, but look very conductive at high voltages. This possibility can be eliminated completely by removing the kill switch wire. Remove the pin or cut the wire to the harness (you can always solder it back). Then check for spark. This eliminates all kill switches - all of them - end of story. But be aware, if the quad starts you will have no way to turn it off. So be prepared to hook it back up to be able to stop the quad - and remember that it has high voltage on it so you just can't grab it with you fingers to reconnect it. Use insulated pliers or whatever.

Two more data points that might shed light:

1) Disconnect the CDI, and measure the kill switch voltage while cranking the engine. This waveform is complex and consists of AC and DC components. Measure both AC voltage and DC voltage on this pin and report both. What this measurement does is look inside the CDI internal supply voltage.

2) With the CDI disconnected, set your meter to measure AC current on a 200 mA scale (or so). While cranking the engine measure the output current to ground on the AC power pin. You are shorting the stator ignition power pin to ground when when doing this through your meter. The short circuit current is another verification that the stator can put out power as well as voltage. Power is voltage times current. Shorting out your stator will not hurt anything.

With the last two tests I'm just looking for more clues.

[Cal25]

Lynn, I must say you are a much valued resource here. Thank you very much for your detailed help.

[MICRider]

Originally Posted by Cal25

Lynn, I must say you are a much valued resource here. Thank you very much for your detailed help.

I second that, LynnEdwards knows a tremendous amount about electrical, I wish I was as knowledgable

[Weldangrind]

Originally Posted by MICRider

I second that, LynnEdwards knows a tremendous amount about electrical, I wish I was as knowledgable

I think that we all have the opportunity to learn each time LynnEdwards posts.

[TurboT]

Originally Posted by Weldangrind

I think that we all have the opportunity to learn each time LynnEdwards posts.

Unless it goes right over your head like the last post ... 8O

All kidding aside it's wonderful stuff and one day when I haven't been sniffing too much glue I will re-read and try to take that all in.

Thanks for your contributions, LynnEdwards.. hopefully it helps the authour of this thread find the gremlin, and others to follow!!

[Turnburn99]

Originally Posted by Weldangrind

I think that we all have the opportunity to learn each time LynnEdwards posts.

I agree, there has been a terrific amount of valuable information shared on this thread and many others. This is a great site with many knowledgeable helpful people! Thanks to all! I hope that the trouble with your quad will be sorted out soon.