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Timing chain

21728 Views 24 Replies 6 Participants Last post by  Scorpyon
Ok, next on my verification check list is the timing chain. I've looked through the service manual and it seems to be quite the process. Lots of stuff to take off and special tools are needed.

Does anyone know of a simple way to just check the timing chain for slack without taking the motor apart?

The reason why I want to check it is because I hear a ticking sound from what seems to be the middle left side of the engine. Below is a video from one of my first posts. The sound is less noticable when the engine is cold but when it warms up, you can't miss it.
You can hear the high pitched tick sound when I let go of the throttle.

Oil has been changed, valves have been adjusted and everything is tightened down (no rattling exterior parts).

Suggestions are welcome.
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I had an 02 Griz that had a very similar sound and it seemed like it was coming from the left side of the engine just like yours. Mine only had 1200 miles on it (I bought it with about 930 miles and big mud tires). The CVT had been reassembled incorrectly (roller weight fell out) and as a result the wet clutch was burned up from trying to turn the Outlaws. I had an ATV/sled shop replace the wet clutch and the sound went away. I wouldn't swear that you have the same issue but it might be worth a look since yours has higher miles.
To check the timing chain, just remove the timing chain tensioner and check it's travel. How far is it out?
If it's not completely out of travel as per the manual, then your timing chain stretch should be good.
I had an ATV/sled shop replace the wet clutch and the sound went away. I wouldn't swear that you have the same issue but it might be worth a look since yours has higher miles.
I've already checked the wet clutch and it's still good to go. The housing has faint grooves in it caused by the wet clutch but nothing to be worried about and the primary sheave has been replaced so all is good in that area. There was no play at all on the wet clutch shaft either.

So my next step is checking the chain. Thanks for the input!
I've already checked the wet clutch and it's still good to go. The housing has faint grooves in it caused by the wet clutch but nothing to be worried about and the primary sheave has been replaced so all is good in that area. There was no play at all on the wet clutch shaft either.

So my next step is checking the chain. Thanks for the input!
Got it! Glad to hear those things all checked out. Sorry if I missed another thread with this in it. I'll be watching to see how you come out. We have a couple of 660s in the family so I'm always trying to learn.
To check the timing chain, just remove the timing chain tensioner and check it's travel. How far is it out?
If it's not completely out of travel as per the manual, then your timing chain stretch should be good.
I've removed the chain tensioner but I don't see how you can identify a stretched chain that way. The tensioner is self tensioning and when I remove it, it fully extends. Once fully extended, I put it back in it's place and it presses against the chain guide and there's at least a 1 inch gap between the tensioner cap and the crankcase. So, the way I see it is, the only way for the tensioner to be fully extended when installed is if the chain breaks.

Does my analogy make sense?
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Now this is just a WAG

What if you take a piece of dowel rod that will fit in the tensioner hole. Press it tightly against the chain, mark the dowel at the mounting location of the tensioner. Then compare this index against the fully extended tensioner.

Also you may also be able to rotate the crank slightly in the first forward direction then in the reverse direction with the dowel in place to see how much defection the chain has.
Now this is just a WAG

What if you take a piece of dowel rod that will fit in the tensioner hole. Press it tightly against the chain, mark the dowel at the mounting location of the tensioner. Then compare this index against the fully extended tensioner.

Also you may also be able to rotate the crank slightly in the first forward direction then in the reverse direction with the dowel in place to see how much defection the chain has.
I'll try that. Thanks for the tip!

WAG? I'm having trouble deciphering..
Wild A$$ Guess
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Remove the spring from the tensioner before removing the tensioner itself and it will not extend anymore when you remove the tensioner. Then you can accurately see how much extension is left in the tensioner.
My post above is incorrect. I was thinking of a different tensioner. I forgot the style of tensioner the 660 had.

I work on too many of these things.....Just gets lost in translation of everything.
?
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Well, looks like I'll probably have to take some covers off to get to inspecting the chain. I'll try reogem's suggestions above first but if it comes down to having to dig into the engine....

Does anyone know what's the best access point to see the chain? Valve cover or stator cover or both?
I found a video where a guy explains how to check if your timing is off because of a possibly stretched timing chain. If you watch the video, does anyone have anything to add before I dig in?

I ordered a flywheel puller yesterday and got it today. Now that was fast. Got it from FortNine. Their warehouse is in Montreal which is only 2 hrs away but still, next day delivery is awesome.

I'll be inspecting the chain soon. Probably in about a week. I really want to find out what that noise is.

More to follow.
I'm anticipating work on my Grizzly and I was wondering... When I replace the chain, I'll have to re-time the cam using the "I" mark on the flywheel. When would I have to use the "H" mark? I think it's for ignition timing (or something like that) but when would I have to adjust that?
I might have found the source of the noise.
Is it the wrist pin or is it down on the crank?
Any thoughts?

Also, is the oil pump chain way too loose?


Any feedback is welcome. Thanks!
Anybody?
My oil pump chain looks like yours. I'm replacing it, you're in that far already and the chain was like $30 or so at my local yamaha dealer. I'm also adding an oil cooler. Chains stretch like that when they run hot.

Sent from my SAMSUNG-SM-G870A using Tapatalk
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My oil pump chain looks like yours. I'm replacing it, you're in that far already and the chain was like $30 or so at my local yamaha dealer. I'm also adding an oil cooler. Chains stretch like that when they run hot.

Sent from my SAMSUNG-SM-G870A using Tapatalk
Thanks for the feedback. I will change it but I'm wondering if that kind of slack is normal. Also, the water pump gear is quite wobbly. I don't want to replace something to find out that everything is just as loose after.

Someone posted a similar question in a very old post but never got a response.
Sorry for not seeing this earlier.

The oil pump chain is not supposed to be really tight. It has slack in it. But yours seems stretched to me going only by watching the video. I would replace it if it were mine.
The reason why nobody has posted a actual deflection measurement is because the manual does not list one. At least my factory manual does not.
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