Hi All,
I have a 02 blaster that is at this point driving me crazy. The only good that has come out of it is that im learning how to do the work on my own. It started after I purchased the quad about a year ago that there was a problem with the compression. I had a friends great motorcycle mechanic take a look at it. (he hates to work on quads). I had mentioned to him that I thought it was a electrical problem but he insisted it was not starting because of low compression. So I went ahead and got a Vitos Big Bore Kit and had him put it on. He called after it was done, I picked it up got it home and im still having the same problem starting it... $600.00 later at least it now has a new top end. This was 2 months ago. Yesterday I did get it started. I let it warm up and took it around the block. About 5 mins into the ride, it bogged out and I gave up after a 2 hours trying to start it again. Today I tried a few things to trouble shoot the electrical system myself and was hoping someone here can help me narrow down why its still not starting. This is what I did so far:
I took off the flywheel cover and found it to be alittle rusty because of a bad gasket. I sprayed a cleaner into the flywheel hoping it would do something to help but it didnt. I dont have the right tools I need to take off the flywheel to look at the stator but will get if its needed.
I took apart all the wiring at there connections and cleaned them with a contact cleaner spray. I checked and made sure nothing was grounded out and didnt find anything.
I checked the ignition switch with a tester and its working as should with the key in.
This is where I got stopped today:
While checking for spark with the plug out I put my finger directly on the bottom of the plug and had someone kick it. I should have gotten a jolt but only felt alittle current go into my finger. My question is how do a narrow it down between it being a bad magneto, stator, CDI or Ignition coil without having to replace all three. Or it is maybe another problem that I am overlooking. If anyone here has had a similar problem or knows how to help, it will be greatly appreciated.
Thanks in advance,
John

 

Been there.... my case it was the Stator was bad.

 

Thanks for sharing. Any idea on how I can narrow the problem to the stator and not something else?

 

Test continuity of the Stator..... or check the output of it at kicking the motor over and look for some sort of sign of life..... The Stator is actually a set of coils for multiple purposes.... My 96 model has a coil for the headlight and one for the rest of it, and there's a tiny pick-up coil for the ignition, if I remember right..... There's a parts breakdown on the Yamaha Motors Website that shows it clearly... it's under "Generator" in the Blaster area.... You can buy each coil for the stator separately also. so you can keep "replacement testing" costs down.

You'll have to get a wiring diagram to test everything properly though. I'd recommend one of the online manuals from ebay as a quick way to get the needed info. I have a hard copy at work.....

 

I have the service manual with the wiring diagram. What I would like to know is if I was getting even alittle current to the spark plug when I was kicking the motor if its possible that it could be the CDI unit or because it is where the orange wire that comes from the stator and goes through the CDI unit ends, could it be the Ignition coil is bad. In the manual it shows you should be able to take off the spark plug cap to test the wire from the coil. On my quad its one piece so I dont know if was replaced before by another owner. I have a good idea on how the system works but its not easy to narrow down the problem.

 

I kind of went about it this way..... Cheapest to the most expensive. I started at the Spark Plug, Then the Plug cap/end, then the coil, then the stator..... I had spares of all but the stator, so it was the last. I never got to the CDI, so I found it to be good. I did, however, find a very poor ground on the coil, when I took it off to check it out. cleaned up the ground and re-attached with Dielectric grease, to make me feel better anyway. What I found, was the stator was actually intermittent when it got hot. It would quit completely. Then after it cooled back down about 20 minutes, it would run for a few more minutes.

One day I was riding and got about a mile from my truck, and the thing quit completely and never again worked..... That made it a bit easier to find the issue. I have heard of bad CDI boxes, but not many, so I don't start there at all. They're a bit pricey also, so like I said,.... I started with the cheapest part first (priced all of it one piece at a time, and found where to start), and went to town changing parts. Do check out that ground wire to the Coil though, it's a non replacement thing,... but a maintenance one instead.

 

I was kinda thinking the same as where to start. I already changed the spark plug three times, and I know its not a fuel problem. I even sprayed a starting fluid into the cylinder when I had the plug out to see if would start and it didnt. I wasnt sure how to go about the spark plug wire, in the service manual illustration it looks like the cap the goes to the spark plug should be able to come off, but on mine I dont see where I would be able to pull it apart. It appears to be just one wire with the ignition coil attached. Is yours the same? Thanks again for your help with this problem. I would really like to get it running already. I had it now for almost 1 year and only used it 3 times all totaled less then 5 hours with the old top end, now I have the Big Bore Kit on it and would like to be able to take it for a ride and not have to worry about pushing it home.

 

The spark plug end cap "Unscrews" on mine. But you should be able to test through and around all that with the home-made spark tester the manual suggests. If it's got the proper continuity it should be OK. Rarely do I find anything that reads through, to be an issue on these coils. If you try too much to get a spark without the spark plug grounded, you can screw the pooch on the CDI. It takes a bit, but it can happen also.

 

Straight up sounds like a coil problem to me....There like 30$ or so ,buy 1 put it on....


Your stator shouldn't evan be faintly close to needing replaced. The one in mine is still good 12 years later! I also just replaced the stock coil 12 years later.

 

I hope its not the stator..Im gonna start with the coil and work back from there if its needed. I priced everything out and its def the cheapest to fix. Hopefully it will fix the problem. Thanks for your help!!