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Discussion Starter · #1 ·
Okay I have a 2002 Grizzly 660 that was running all over the mountain last weekend and then just stopped. Tried starting for an hour or so then gave up and pushed into the back of my truck.

Now that I have had time to tinker with it I am at a loss.

I replaced the coil, spark plug, checked all fuses, all connections tight, made sure battery was charged up with no luck.

It will turn over and and does not try to start, It has spark as I pulled the spark plug and touched against frame and it sparks. I removed the air filter box and shot starting fluid into the carburetor and it didn't even try to fire.


HELP any advise before I bring it to a service shop where it will cost me$$$.

Thanks
 

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What colour is the spark? If it's yellow or orange, that's weak spark. The spark must be blue to almost white.

Is the kill switch on the left handlebar turned off? It shouldn't crank over with it off, but stranger things have happened.

Since this happened all of a sudden, then it must be some kind mechanical or electrical failure. It could be a failed electrical component giving bad spark, to a broken timing component.
It's not a fuel related failure due to the simple fact it would not start on the ether (starting fluid).

If you have good, blue spark at the plug, then check timing. If timing is ok, then pull flywheel and check the woodruff key for shearing.
 
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Discussion Starter · #3 ·
Hi Dezz

So the Color of the spark is BLUE... Kill switch is in correct position. It won't even try when it's in the off position.

I took a quick video of what it is doing. Still wouldn't start over with a good battery this morning..


When I stop cranking the white relay just clicks.
 

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Going only by the sound of the cranking, I think you got a sheared flywheel woodruff key.
 
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CRAP.. Not sure if that is in my capability.... I did a quick look and didn't see any how to's online...
Remember, this is what I "think" is the issue. It may be something else. Try to rule out everything that you can before assuming the woodruff key is sheared.

Without being able to actually be there to troubleshoot it in person, and going solely on what information is known so far, my best guess is a sheared flywheel woodruff key.
 

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Dezz

I am able to pull on the rope pull cord and can hear the cylinder cycle. Would I be able to do that with the Woodruff key sheared?
Yes. Everything will still rotate like normal. Even the timing marks will line up in the Windows as they are not effected by the flywheel.
Unfortunately the only positive way to check for a sheared key is to pull the flywheel. It's not hard to do. But you will need a puller for the flywheel.
 

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Crap.. Pulley puller only had two of the three bolts .. Couldn't get it off.. Have to wait until tomorrow when I get the right tool.. Coolant smelled horrific..
If the right tool you will be getting is a flywheel puller like the one below, good.
I've read that a 3 legged puller is not recommend because of a risk of warping the flywheel or it not coming off straight. Also, before using the puller, screw the starter pulley bolt back into the end of the shaft. It will prevent damage to the shaft end when using the puller.
 
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Discussion Starter · #11 ·
Bought the specialized flywheel puller off of ebay and got it off on the second try. Bad news it wasn't the woodruff key. It's in still looks fine to me. Orginal below. It's has a slight mark on it but don't think it's bad enough. I put a new woodruff key in and put slightly back together. ANYTHING else I should do before putting back together???
 

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I missed it the first time because of where the comment is in your post, you said when you STOP cranking the white relay just clicks?

Is that relay part of the kill switch etc. system? Do you have access to a wiring diagram for the machine?
 

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Thought about it a bit more, but does this machine have a cut off if the fan goes out? Pardon my ignorance, but some machines have something built in if the cooling fan stops working it causes a fuse to blow and the machine won't start until the fuse (or something) is replaced. It forces the user to fix the fuse and look at the problem before they burn up the engine. I wanna say artic cat has something like that on their machines? It just kind of made sense to me if you were running it and it shut down, the coolant is in bad shape, and it won't start. I'll shut up now and let the real experts help you out more. I was just thinking the fact that the relay is white could mean that it has been replaced? But they all could be that way, I have no idea. I'll shut up now...
 

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Thought about it a bit more, but does this machine have a cut off if the fan goes out? Pardon my ignorance, but some machines have something built in if the cooling fan stops working it causes a fuse to blow and the machine won't start until the fuse (or something) is replaced. It forces the user to fix the fuse and look at the problem before they burn up the engine. I wanna say artic cat has something like that on their machines? It just kind of made sense to me if you were running it and it shut down, the coolant is in bad shape, and it won't start. I'll shut up now and let the real experts help you out more. I was just thinking the fact that the relay is white could mean that it has been replaced? But they all could be that way, I have no idea. I'll shut up now...
Yamaha's don't use any sort of system like this.

Since we have confirmed the flywheel key is good, timing is good and you have good spark, the only thing left is compression.
Without compression, it doesn't start. Since this happened all of a sudden, some kind of mechanical breakdown must of happened.

Do a compression test to see what kind of compression your making. A leak down test would be better if you have access to a tester.

Did you 100% confirm timing is good? Is the timing chain slack? Did it possibly jump a tooth on the timing chain?
 

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Discussion Starter · #16 ·
Plan

My plan is to put the flywheel back on and get everything buttoned up. I will try the compression test as well as the pick up coil and rotation coil test.

Feel like I am chasing my tail but thank guys for the help. Really appreciate it.
 

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My plan is to put the flywheel back on and get everything buttoned up. I will try the compression test as well as the pick up coil and rotation coil test.

Feel like I am chasing my tail but thank guys for the help. Really appreciate it.
Chasing your tail leads to an end at some point.

Unfortunately it's the best we can do without actually being there to troubleshoot it in person for ourselves. There is so many things that can cause a no start issue.
 
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My plan is to put the flywheel back on and get everything buttoned up. I will try the compression test as well as the pick up coil and rotation coil test.

Feel like I am chasing my tail but thank guys for the help. Really appreciate it.
Best test the pickup and rotation coils before you put it back together. If one is bad you will have tear it all down again to replace it.
 
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Having trouble checking pickup coil. I can trace it back to these plugs but can't seem to check it for resistance. AM I doing it right?
Yes you have it correct. That is the right connector. Just resistance between the correct wires (I can't remember for sure which ones).
 
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