Lets do the Yami RATTLE

Lund

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So i thought i would post this thread for all you new Side Winder rider's before some start asking or saying.
"my clutch rattles" i need to fix it, shim it, replace it....Don't fear the Yami rattle, it ain't your clutch.
This thread applies to all Yamaha 4 stroke excluding the Apex.
So the Nytro's, the Viper's and Side Winder's.
If you haven't already noticed you will soon enough start to hear a rattle most noticeable at or near idle.
Unfortunately it is a sucky sound that is very annoying and embarrassing to say the least. Especially for the fancy mod guy's running around.

"So what is the rattle if its not the clutch, sure sounds like a clutch"

So here is the deal on these 4 strokes.
Like all 4 strokes in the automotive world the crank run's BABBITT shelled bearing's. These are absolutely the best bearing's to run on any high HP motor as the crank is suspended on a cushion of oil and never contacts the bearing.
So for their intent babbitt bearing's for rotational/reciprocal motion work great.
BUT they cannot handle the side load applied by the typical snowmobile clutching system. So Yamaha solved this problem by the use of a STUB SHAFT supported by ball bearing's. This is the actual tapered shaft your clutch is mounted on, it is NOT the crank shaft.
The stub shaft and the crank shaft are connected by spline. Crank is female splined and stub shaft is male spline.
As new these are relatively tight but as parts wear in some play will developed.

That my friends is the rattle and nature of the beast.

There is a temporary fix, you can use 680 green loctite and loctite the splines, i also recommend the use of a loctite primer. It will 100% remove all the rattle but it will not last.
I usually do my sled 2 times a season. I have done it so many times now that it is a 1 hour job to do. Easy Peasy.

BTW, i will be doing my Side Winder, its just starting to get rattly.
 

teeroy

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does the rattle get worse to the point of spline failure if not addressed? a friend just bought a sidewinder this season and is having belt trouble, 3 so far which I'm pretty sure is unheard of on Yamaha sleds, boosted or N/A. pretty impressive ride tho, his sure rips
 

Lund

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does the rattle get worse to the point of spline failure if not addressed? a friend just bought a sidewinder this season and is having belt trouble, 3 so far which I'm pretty sure is unheard of on Yamaha sleds, boosted or N/A. pretty impressive ride tho, his sure rips

The design has been in use since 2006, i have never heard of a spline failure.

I need to clarify my post a bit.
The wear that takes place between the splines is completely normal and will not cause belt issues or spline failure. The only inherited issue is the rattling noise.
The noise come's from the clutch but is caused by the spline.
There is no reliability issues with the set up other then an annoying rattle.

Your friend most likely is having a clutch issue, maybe related to calibration or mechanical problem with it. There were some units having secondary roller issues, roller developing flat spots.
 

teeroy

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The design has been in use since 2006, i have never heard of a spline failure.

I need to clarify my post a bit.
The wear that takes place between the splines is completely normal and will not cause belt issues or spline failure. The only inherited issue is the rattling noise.
The noise come's from the clutch but is caused by the spline.
There is no reliability issues with the set up other then an annoying rattle.

Your friend most likely is having a clutch issue, maybe related to calibration or mechanical problem with it. There were some units having secondary roller issues, roller developing flat spots.
thanks, I'll mention the secondary issue to him. they've done a few calibrations to the primary and added a shim to adjust deflection but it squeals at idle now when it's hot.
 

Lund

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Before long i will do and put up a video on how to lock the splines on your Yamaha. Step by step procedure and tools needed on doing it your self.
IMO, it best to do it while the play in the splines is limited, the process of the loctite spline goes longer in service then allowing excessive play to develop.
I will be doing my Side Winder.
 
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