Worn primary sheaves

[reeltime-brad]

Help I have a 2005 rx1 with a badly worn primary clutch sheave,there is a dished out area in the middle of the moveable sheave and large grooves at the bottom of both sheaves.Just had to replace a blown out chaincase side driveshaft bearing. All other bearings looked okay althouth they were dry. Any help with why the clutch is so worn would be greatly appreciated. I have not checked alignment yet,wondering if clutch tool for v-max sleds would work? also what would make a good replacement clutch.Sled has 5,000 mi. And a lot of holeshots.

 

[benny]

I had both the primary sheaves replaced on my 08 Nytro under waranty. They had the excessive groving down low on the sheaves because, get this, the Yamaha belts are so hard. They actually wear away the aluminum at idle. I don't think the new ones are wearing as fast as the original sheaves, but it might be psycological.

 

[aVenture]

Holeshoot or not they all do it.. at the bottom. RX being worst than the RS. But the 3 holer is worst in the middle from what i have observed.

Get it to someone than have a lathe & sand it flat again.. way cheaper than a replace.

Did it twice on mine already (i own a lathe) but i have 4 times your mileage.

 

[reeltime-brad]

I have access to a lathe but i'm concerned that thining the crosssection of the sheave would weaken it, hate to see what happens when one explodes. Is there a belt that is easier on the clutch.

 

[Len Todd]

That is a very valid concern.

 

[LazyBastard]

You definitely do NOT want to be thinning it down. Trust me on this... it is VERY bad when they blow. I had a fixed explode on an Exciter once, and that motor turns only 7500 max. On this engine, you're looking at close to 9000. Although unlikely to make you dead since its not inline with you, it will cause SERIOUS damage to your sled, could EASILY throw chunks through your leg and foot, and could make dead other people in front of or behind you.

As for other belts that don't wear down the clutch as bad... ANY other brand of belt will wear the clutch less, I've had a great experience with GATES belts -- in my opinion, just as durable as OEM 8DN belt, but non-abrasive against the clutch and sticks to the clutches a lot better.

 

[reeltime-brad]

Thanks alot for the info.Still looking for what to replace it with as the only part # match is another RX1. I'm not sure what differences there are between say a SRX and the RX1 but the part# does not match?

 

[LazyBastard]

I believe that an SRX fixed should be a match. The sliding is different though. Can't see why it would matter what the part comes from though -- you want to replace it with NEW, not much sense replacing a worn part with another worn part.