It isn't a good idea to remove the plug wire with the engine running (or even cranking). You need a path to ground for the coil high voltage plug wire to arc through, otherwise the voltage on the coil builds up to tremendous levels. The coil could break down internally and damage the coil. Or it could arc over internally to the CDI through the primary winding and take out the CDI. This why the classic spark test has you hook up a spark plug and hold the plug threads against ground. It gives a discharge path to ground that is the easier to arc through than any other path that may do damage.

That said, I've accidently knocked off my plug wire (or forget to hook it up before cranking away) many times without ever causing damage to my coil or CDI.

Let's find the CDI first, see it is anything like a generic CDI and decide what to next at that point.

 

Lynn, this is the CDI. This part looks like the exact same thing as on my quad. mines not a yerf dog, but this part is the same. same color too.

2000 YERF DOG 90CC ATV CDI : eBay Motors (item 160420644602 end time Apr-11-10 17:59:59 PDT)

 

also, can stators go bad from sitting? i mean the quad sat for about 2 years, but i was getting intermittent spark up until last sunday. i mean i read that they wont go bad from sitting. the last time i tried to start the quad about 2 years ago i got intermittent spark as well, and about 5 months before that was the last time it ran properly.

also Lynn to add to what you were saying, the boot on the plug popped off about 3 times that day. today, i was taking the plug out again and the boot fell off...i looked and it looked like there were threads, so i tried to screw it back on. it went on and seemed much tighter. the threads however were very dirty and almost rusty. still no spark. also i might add i've been kicking it the whole time, not electric start because i don't have a battery. not sure if that makes a difference. also i can't find that CDI anywhere online...

thanks again for your help, its greatly appreciated.

 

I've never seen nor heard of that CDI. Here is another recent post about a monsoon atv CDI where it was claimed that monsoon was bought out by yerf dog. The wire colors match the colors in your CDI picture link.

http://forums.atvconnection.com/kids...g-diagram.html

You might want to PM Toby Cheeseman and see if he knows more about this CDI.

I also don't know any specifics about your Sundiro quad. Can you post pics of the engine? I'm just wondering if it is similar enough to other more generic chinese engines such that another CDI /coil combo can be wired in.

Stators are just coils of wire that have magnets (mounted in the flywheel) whizzing by. A coil of wire shouldn't degrade over time span like 2 years. It could degrade when hot, or wet, or powered up, but none of these conditions last for very long on an idle quad compared to two years. Things cool off, dry out, etc.

So you found a link showing your CDI. Any chance you also found a link showing your Stator?

 

No, no link showing my exact stator, but in a previous thread, someone took out the stator of a sunray 50 and he said it had 6 coils. that's about all i know. i'm not sure exactly where the stator is nor how to remove it, i've read that i'd need a flywheel puller, and i've looked and i have no idea how i'll find the right one to fit this quad. i'm hoping the stator is ok, i hope i don't gots to replace that, but if i do i do i guess....i mean it was sparking last week, but i guess it could easily have gone bad could it have? does that seem really possible? i mean i obviously hadn't run the quad thru water or anything, but i guess it still could've went? i don't know. maybe i messed the coil or even cdi up by popping that boot off like that. it just seemed odd that i hit the boot then it stalled then no spark. that day, in the span of 20 mins or so, i shut the quad off about 4 times, and each time it started right back up first kick. i mean before i cleaned the carb it had a relatively good spark. it appeared intermittent to me, but it started everytime i tried, i just couldn't see the spark every time. granted, its hard to see a spark in daylight, against a yellow plastic quad, and while i'm trying to kick it over. lol.

i found a test on another thread regarding checking the electrical system, and next chance i get i'm gonna try to do the test. i'll borrow an ohmmeter and try it out. i was under the impression that sundiros are similar to etons, so i'll use the eton measurements he posted as a guide.

Also another question, when checking the electrical system do i need to use some sort of a battery? or can i still use the kick? also, when i'm testing the stator output thingys do i need to crank the engine? i would think i did have to, but i figured i'd ask.

Lynn this is about the closest I can find to an engine picture online. Its dark now or i could take some now.
http://www.coltsportmotors.com/17402.2/index.htm

 

Lynn-

I followed up your suggestion about PMing Toby Cheeseman, and so far he's been extremely helpful, that was a great idea. He's going to send me a CDI box and ignition coil to test on my quad. I will be sure to let you know what happens.

Thanks again for all your help.

 

I was trying to see if the engine or stator looked like anything chinese generic. If it does then there is always the possibility of rewiring and putting in another more generic and readily available CDI and coil set that matches the stator.

Fortunately the stator is relatively easy to measure. The three outputs (high voltage ignition power, ignition timing trigger, and battery charge windings) can be measured with a voltmeter. But it is much nicer to have a constant cranking speed so that the results are well defined (all 3 outputs are proportional to engine speed), and so that you can measure them while not distracted by jumping up and down on the kick start.

In that same link to the monsoon wiring diagram question I posted before there is now a wiring diagram posted by Preed. The wire colors don't match Toby's wiring instructions, but the diagram shows that the CDI is "Eton like" in that the kill switch connection must be grounded to get spark. This is backwards from the generic chinese CDI's that must have the kill switch pin disconnected to get spark (grounding it kills spark).

Can you post (or send me) a link to the the other electrical test thread? I'd like to take a look at it.

To test the electrical system (other than the battery or the starter circuitry) you need to turn the engine which turns the stator. But as mentioned before it makes thing enormously easier if for each test you do the measurements are taken with the engine turning at a constant speed. That's hard to do with a kick start. Using the kick start adds another confounding variable to the equation.

 

Awesome. Let's hope that sheds more light on the problem.

 

Lynn-

I will find that post right now and send you a link to it. I'm thinking more the stator may be ok. I haven't got the chance to test it yet, prob not til next weekend. It was working last weekend fine. What causes them to go bad? Are they like starters where they have a lifespan and then they stop working? Still it could be bad i know, but i'm trying to be optimistic.

It looks like this CDI matches up to mine, in the link i sent you. The wires look similar to me, i'd have to check on the quad which i won't be able to until next weekend at least. No REV LIMIT CDI MINI QUAD ATV SCOOTER ETON JOG 90cc : eBay Motors (item 150432660696 end time Apr-18-10 08:05:10 PDT)

Another stator question: does the stator create spark while the quad is running? I'm guessing it does. What i mean is, when the atv stalled on me last weekend, could that be the stator just going bad? Just quitting i mean?

 

I'm starting to really think its the coil. I mean that weekend, it seemed to start fine. Then I got it running, popped the boot off a few times, then nothing. I've been looking many places online, and the CDI may be fine, but the coil could be bad. I think I might have fried it lol that last time i knocked the boot.