[Primethious]

When I modded my wet clutch I forgot to use loctite on the lightly torqued tiny bolts that hold the housing on the engine. Eventually every one of those tiny bolts loosened up (one backed all the way out) and that started an oil leak that went right onto the sheaves and then drive belt.


I got the whole thing apart, and plan on adding a shim to the setup while I'm at it.


My question is there anything that can clean a drive belt properly and save it after it's had oil on it, or do I need a new belt?


I'm considering the Gates Carbon belt if I have to change it.

Opinions?



Is brake clean ok for the sheaves themselves...I would have thought so, but I have heard something negative about it. Not sure if it's BS or not.

 

[Vincent]

Yes adding a shim is a great idea! Can you check your CVT ratio to?

No need to change your belt. My quad also had a wet clutch oil leak witch covered my belt with motor oil. That was 3000 miles ago and my belt still looks new.

Just clean your belt and sheaves with NON chlorinated brake cleaner and ride on. I've always cleaned all my belts and sheaves surfaces the same way on many sleds and quads with Zero issues.

P.S Also recommended you stick with Yamaha belt as they are well documented to out last the majority of after market. Many Grizzly and Kodiak owners have gotten 10 000 miles on their original belts!

 

[Primethious]

Thanks, and that sure helps!


I've got a gasket on order, and will order a new left handed lock nut for the wet clutch.
Meanwhile I'll get to cleaning!
I checked my ratio before I pulled it all apart, and with the JBS sheave and no shim I was at about 2.8:1. Gonna order some shims and see how that goes.

 

[Vincent]

Thanks, and that sure helps!


I've got a gasket on order, and will order a new left handed lock nut for the wet clutch.
Meanwhile I'll get to cleaning!
I checked my ratio before I pulled it all apart, and with the JBS sheave and no shim I was at about 2.8:1. Gonna order some shims and see how that goes.

Awesome and Good luck!

 

[CanadianKodiak700]

just make sure to clean your belt really well and let it dry, once it's dry, clean it again. rubber is porous , and can pick up more oil than one would think.

As Vincent said, stick to Yamaha for a new belt. They are another piece of the puzzle as to why this CVT design works so well. I haven't read a thread yet. nor seen a video of an aftermarket belt outlasting stock in normal conditions.

 

[Vincent]

The reality is you didn't make a mistake, those bolts don't come from the factory with locktight.
Though it is odd they loosened......

 

[Primethious]

Yea, I kick myself in the butt already for not adding the loctite. It's a regular thing for me.


Now I'm wondering if I only snugged them down and forgot to go back and loctite and torque them. Very rare for me to make such a mistake, but we all F up. Anyway nothing got harmed luckily.

 

[Primethious]

I called JBS and he didn't really recommend a shim when using his sheave, but he said a small one could work...50 or a 75 at the most.


I got them in the mail today, and placed the 75 on it. The outer edge of the sec is riding at about the thread level on the belt which means the outer teeth of the belt are outside the sheave. Would this wear the belt weird? Where is the limit to keep things reliable?

 

[Vincent]

I called JBS and he didn't really recommend a shim when using his sheave, but he said a small one could work...50 or a 75 at the most.


I got them in the mail today, and placed the 75 on it. The outer edge of the sec is riding at about the thread level on the belt which means the outer teeth of the belt are outside the sheave. Would this wear the belt weird? Where is the limit to keep things reliable?

It's fine, remember that the belt always has full contact against the primary sheave surfaces so the belt will always wear even. Also the belt drops below the secondary sheave edge passed 5 mph anyways. Again adding to the fact that odd belt wear won't be an issue.

Like you my belt cords also sit flush with the edge of the the secondary sheave since installing my Coop45 machined sheave with an added 0.5 mm shim. I end up at slighter over 3:1 initial ratio.

Also your belt will rub the plastics a bit as the cvt functions witch can leave rub marks the top teeth of your belt. This is normal with these higher ratio sheave mods as you are pushing the limits of what clearances the Cvts were designed for. But the belt will wear in its own "clearances" after a short period of time. I've racked up 2000 miles with my belt having evidence of rubbing on it teeth without issues.

If any of this is a concern to you just use the smaller shim, and ride on......

 

[Primethious]

Thanks Vincent!


That gives me some peace of mind.

 

[Primethious]

There are 24 equal segments of the primary sheave so that's 15 degrees per segment.


I was aprox 1.4 segments short of a third rotation.
1.4 / 24 = 0.05833

1 - 0.05833 = 0.9416
2 + 0.9416 = 2.9416

I used a piece of bent wire bolted from the plastic housing and had it pointed down to one of the ribs on the front of the pri sheave to be as accurate as possible.
Just tested the ratio and I'm at aprox 2.94:1 using the 75 shim on my setup with the two sheave bolts tighten to hand tight.


Looks like the Coop45 pri sheave is better for getting a lower starting gear ratio than the JBS sheave.
If I ever go with bigger than 26" tires I may look into one of those.


Now just got to get things back together.

 

[Vincent]

Interesting.....

I was at 2.8 :1 with 1.5 mm shim
2.9:1 with my coop45 sheave
3.05:1 with the Coop45 sheave with 0.5mm shim

Bang for buck 5 $ shims are hard to beat!

Also remember belt wear effects this to.
An older belt will yield slightly lower initial ratios then a new one...

Thanks for sharing your info.