Hello,

My neighbor asked to look at his daughters FSN 110. It's getting no spark, he just replaced the stator about two weeks ago and tested the CDI out on another quad and it worked fine. I tried to test the stator yesterday with a meter and no matter what combination of wires i used i got no readings. I'm going to try to bypass the safety switches today. Any help would be greatly appreciated. Thank You!

 

Does the CDI look the following picture, or does it have only four pins?



The one in the picture above is the most common one so I'll assume that as a starting point. If you have the four pin CDI then we will have to start over.

The most common cause of no spark is in the kill switch wiring. Unplug the CDI and measure the resistance of the kill switch connection in the wiring harness to ground. It should be open (infinite resistance) to get spark. If it is shorted to ground (which kills spark) then check all your kill switches and wiring to see which one is shorted. The possible kill switches are: One pole of the two pole ignition switch, the handle bar kill switch, the tether cord kill switch, and the remote control start/stop module (if installed). Unplug them one by one to find which is shorting the kill line to ground.

If the kill switch wiring is OK then the next step is to check the two spark related windings in the stator (there is a third winding in the stator for charging the battery which we will ignore since it has nothing to do with spark):

Ignition Power Supply Winding: With the CDI still unplugged, measure the AC voltage from the AC Ignition power pin at the CDI plug to engine ground while cranking the starter. You should get about 80 volts AC or so. You should also be able to measure the resistance of this winding to engine ground (engine stopped of course) at a few hundred ohms.

Ignition Timing Trigger Winding: Measure the AC voltage on the Timing Trigger pin of the CDI plug to engine ground while cranking the engine (CDI can be plugged in or not - it doesn't matter). You should see 0.2 to 0.5 volts AC. This signal is actually a bunch of very narrow +/- 5 volt pulses happening at a very low repetition rate so your meter won't measure them very well, but you should see something. You can also measure the resistance of this winding to engine ground. My 150cc quad reads 140 ohms.

Also measure the ground connection pin of the CDI plug for continuity to engine ground. The CDI needs a ground connection to work.

While your at it you should measure the igntition coil primary and secondary resistances just to make sure they aren't open.

 

Hi,

I have the same engine with the same problem and have tried all the checks with the following results:

The Ignition powersupply winding pin I got 80.4 vac Resistance was about 240 ohms

Ignition timing winding pin I had about .57 vac

The wiring for the kill switch and ground were broken so I just left the kill wire (Black white stripe) loose, and reconnected the green ground wire back to it's pin by removing it and recrimping it for now, I'll solder them later.

The coil primary is around .5 ohms and the secondary is in the several hundred ohm rannge (didn't pay that close attn. to it as it seemed good)

The only info missing from the above post was how many volts should I be getting out of the ignition terminal (I am guessing between 80 and a couple hundred). I am getting about 1.9V at the terminal wires to the coil (coil in or out of circuit), so obviously no spark.

I also checked the resistance between the wires going to the CDI and ground and they are fine (.1-.2 ohms)

Am I missing anything else? Also I guess most of the local shops that sell these things will have this part and about how much do they run?

Thanks

Jeff

 

The ignition power winding looks fine at 80 volts AC.

Your trigger voltage is higher than most, but this may just be your meter. The pulses on this pin are not sine waves so different meters measure differently. Just to be sure, measure the resistance of the trigger pin to ground at the CDI connector in the wiring harness. You should see 150 ohms or so. I just want to make sure the trigger winding isn't open, and the 0.57 volts you see is just stray capacitive coupling over to the ignition power winding.

The ignition terminal of the CDI has very narrow high voltage spikes on it(150 volts peak at cranking speeds) with lots of zero volts in between. How you meter measures this non standard waveform varies from meter design to meter design. Most meters will measure close to zero volts most of the time with random spikes interspersed. 1.9 volts steady doesn't sound right. It suggests your CDI isn't getting triggered.

I would recheck the trigger voltage, and check the trigger winding resistance. If those are OK then the CDI would be the likely culprit.

CDI's are cheap on eBay. Several people have reported bad batches recently but at $10 it's not too much of a risk. I wouldn't buy again from the same source if you get a bad one - especially if it works for an hour then quits. They may have thousands of CDIs from the same bad batch.

Or you could search on-line for chinese quad parts vendors.

 

I did get it running, it wa the CDI module. Now on to the next problem starter over run.

Thanks

Jeff

 

Branlee:

Did this help you. i noticed that someone else popped in on your thread. I didnt want your thread to die abcause the other person got theirs fixed and not yours.

 

The OP never answered back after givin a lot of good information. I asked a few questions and discovered that the CDI was bad, but I wanted to know all the tests before just replacing parts. Mine is running fine other than the starter will start spinning because of another problem.

I posted in this thread because of the good info. It should be a sticky.

Jeff

 

Jeff, glad to hear that yours is running. I just was trying to see if the OP was still around. I know allot of times people will post then find the answer and never come back. I hope my post didn't offend

 

None taken, just thought you misunderstood (it was I that misunderstood). I hate reading through a bunch of information just to have the OP never respond to say what the problem was, since so many people will have the same types of problems, thus need simular solutions.

Jeff

 

i hear ya! it's kind of a rip that OPs don't respond to our advice. it's nice to know if it worked or not so others can learn from it.