Installed JBS Sheave - Need Help

Sounds like I need James' help...when a stock Rhino has the same low end as me and can beat me in a short drag race something has to be wrong...like I said before the only difference I feel is that I can get to 49 MPH now (before it was about 40)...but going from 40 to 49 it isn't smooth at all...feels like the rev limiter is trying to kick in and hold the motor back...

I noticed you have the belt on there in the pics without the sheave on.  Are you taking the belt off when you put the sheave on, or trying to tighten it up with the belt on there?  If you try to put it on with the belt on there, you will have a real good chance of not being able to get the camplate up on the splines.

Thread two of your cover bolts in the holes in your secondary sheave to spread it in order to get the slack you need to remove and replace the belt. 

Make sure your camplate slides freely, and your belt is good.  Your weights are in there right.

I don't think grinding the spring to move free will help your problem.

How did it run before the sheave swap?

Pull the secondary apart and see how freely the spring moves in the cups. James has a video on it. You can also try without grease in the clutch. I have a lot less grease in mine cause those ate greaseless weights. I just don't remember all that grease above the cam plate. It's been a while since I been in mine tho. Wish I had better answers for u. After you reinstall everything, take a picture of it. Does your belt stick out the secondary 1/8"????

Was wondering if you knew what the wet clutch looked, don't know if you went that far in? Also, do you have an aftermarket cdi, or still have the factory cdi?

what year
tire size
cdi?

Hump wrote:

I noticed you have the belt on there in the pics without the sheave on.  Are you taking the belt off when you put the sheave on, or trying to tighten it up with the belt on there?  If you try to put it on with the belt on there, you will have a real good chance of not being able to get the camplate up on the splines.

Thread two of your cover bolts in the holes in your secondary sheave to spread it in order to get the slack you need to remove and replace the belt. 

Make sure your camplate slides freely, and your belt is good.  Your weights are in there right.

I don't think grinding the spring to move free will help your problem.

How did it run before the sheave swap?

When first installed I used the bolts to open the secondary sheave...when I tightened up the primary sheave the inner bushing (guess that's what you call it) the center part of the primary was all the way against the back plate (other half the belt rides against)...at that point I didn't really check for the cam plate sliding...before the sheave swap the bike ran fine...it's practically in showroom condition...has around 200 miles and 50 hours on the machine...

banchee6 wrote:

Pull the secondary apart and see how freely the spring moves in the cups. James has a video on it. You can also try without grease in the clutch. I have a lot less grease in mine cause those ate greaseless weights. I just don't remember all that grease above the cam plate. It's been a while since I been in mine tho. Wish I had better answers for u. After you reinstall everything, take a picture of it. Does your belt stick out the secondary 1/8"????

At the time of install I did a secondary service following James' video...I didn't ever try to turn the gold spring after putting it on but I did carry it around by the spring end and it felt pretty tight...like it would not have been easy to turn...

m1n1ster wrote:

Was wondering if you knew what the wet clutch looked, don't know if you went that far in? Also, do you have an aftermarket cdi, or still have the factory cdi?

I didn't go that far into the machine...but the wet clutch has to be just fine with this bike's low hours/mileage...no aftermarket parts...all stock...

WV Hot Rod Rhino wrote:

what year
tire size
cdi?

 2009 700...approx. 50 hours and 200 miles...oem tires...oem cdi...everything is bone stock...purchased the bike used about 6 months ago...farm use only in near showroom condition...

did we talk about different tires and that spring

WV Hot Rod Rhino wrote:

did we talk about different tires and that spring

 Yes...I was going with 28" tires in the future...that's why you suggested the gold spring...

Now that I think about it...when I install the primary sheave and go to tighten up the nut should the lower inner faces (towards the output shaft) be close together (belt riding higher) or does it matter?...when I tightened mine up the first time the belt was riding low on the primary...but again the center bushing on the primary was all the way up against the back plate...

When I put a sheave on, I hold the camplate all the way down in the sheave to make sure the weights don't move until I get the nut on it all the way.  The bearing through the center would be against the fixed sheave and there would be a good amount of space between the two sheaves when I would tighten it up.  If you don't hold it all together good with the camplate against the weights, a weight can jump out of place or flip.  Took me a few tries to figure it all out.  It may just be that secondary spring is to much for those stock tires.

Hump wrote:

When I put a sheave on, I hold the camplate all the way down in the sheave to make sure the weights don't move until I get the nut on it all the way.  The bearing through the center would be against the fixed sheave and there would be a good amount of space between the two sheaves when I would tighten it up.  If you don't hold it all together good with the camplate against the weights, a weight can jump out of place or flip.  Took me a few tries to figure it all out.  It may just be that secondary spring is to much for those stock tires.

 From what you're saying it sounds like I had the primary on correctly...if the gold spring is too much for the stock tires what then is happening/not happening inside the cvt when I'm driving?...

dont run the gold till you put on the tires

WV Hot Rod Rhino wrote:

dont run the gold till you put on the tires

 Ok cool...so just for my learning what is/isn't happening in the CVT while running the gold spring with stock tires?...

wont shift out quick enough

Hey Kenny, It's good to see you over here from Highlifter.

First off, your weights are correctly installed, and the grease looks normal inside the primary sheave. If you are getting a 49-50MPH top speed, then the weights are correct. The problem that you are describing is mediocre bottom end and strangle "shifting" or "revving" sensation as you approach top speed.

I would suggest first reviewing your installation of the primary sheave assembly. If your weights are correctly installed, and grease is not contaminating the faces of the sheaves and sides of the belt then how about the area where the collar goes through the sheave? Is there sufficient grease between those two seals where the spacer collar passes through? I have sometimes noticed that insufficient grease in this part of the sheave will not allow the movable primary sheave assembly to function smoothly. The sheave will "stick" and cause a shifting sensation at high speeds. Additionally, it will not let the sheave close fast enough when you decelerate quickly to a stop or roll and then get back on the gas hard. You will not be in the CVT's lowest gear ratio for the best bottom end torque multiplication.

If that is good and checks out, inspect your cam plate splines for proper engagement. When you install a primary sheave on a Yamaha, the belt needs to be loose and away from the spacer collar. The idea is that you want the cam plate splines to be butted up against that spacer collar and the opposite end of the spacer collar to be butted up against the inside fixed sheave closest to the engine. As other have already suggested, once your sheave is assembled on the bench it is helpful to keep your thumbs pressing firmly against the cam plate the entire time until the splines are engaged fully, the washer, and finally the nut are installed.

We on here have been into the sheaves so many times that it becomes routine. However, we sometimes forget that there is somewhat of an art to installing CVT sheaves [correctly]. It's similar to setting up a ring and pinion gearset. Once you do it, it's routine work. But for someone who may not be familiar with the process it can be done incorrectly.

If, in fact, the CVT was assembled properly and there is no grease contaminating the belt, then I would check the secondary sheave assembly. When you remove the spring, is there sufficient grease in the helix so that the assembly can twist freely? Id the spring somehow binding up because of dirt or a burr in the spring seat? Are all of those pins correctly installed?

Now if all of that has checked out what else could be causing poor bottom end power and that weird sensation at higher speeds? Is your wet clutch ok? Are you using YamaLube or an equivalent "MA" rated oil? The wet clutch inside the motor is oil bathed and needs motorcycle oil to function properly. Regular oil will cause the wet clutch to slip. Could you put your front bumper against a tree or tie off to an immovable object and spin all four tires in low range 4WD? If not, then something is slipping: the wet clutch or the belt. If the engine revs freely or the engine revs and then the tires start to turn then the wet clutch could be suspect.

With all of that said, my personal feeling is that the gold spring is not the problem - even with stock tires and wheels. Too aggressive of a spring or clutching with small tires will simply let the engine rev beyond its powerband. The result is the engine hitting the rev limiter on a full throttle 2WD takeoff on a loose surface like sand. That does not sound like the problem.

I wish you good luck. Keep us updated. If you still can't figure it out try posting a video. Sometimes that can help us better understand what is happening.


 EDIT- James says the gold spring might be too stiff for stock tires. He knows a lot more than I do. You might try that and see what happens.

what color spring should you run if your tires are stock size? but aftermarkert tire.  what is stock..specs.?

Thanks Chris for the welcome and input...I'm going to do what James suggested first (obviously LOL) and put the stock spring back on...if I'm understanding this correctly the gold spring is keeping the belt from traveling all the way to the inner part of the secondary sheave which is why it struggles from 40 to 49...but how do you explain the lower end power feeling the same as a stock bike?...

the rpms are past the power range

now I'm really confused, why does mine run good with 16's, gold spring and stock tire size. Maybe I don't know shit and it actually runs like shit..lol

ASPENDELL ROVER wrote:

now I'm really confused, why does mine run good with 16's, gold spring and stock tire size. Maybe I don't know shit and it actually runs like shit..lol

 LMAO!!!...man you got me...after reading James' spring suggestion earlier your initial post was the first thing I thought of...either this dude's got issues or he got lucky...

aspens is heavier and running in sand so lighter weights and heavier spring would do better

phewww, you know after a long hike, this bike kicks ass! All I know is with JBS set up and advice, its a blast to drive. I can't imagine how fun it will be with an engine...lol

I switched the springs last night going back to the oem spring...hopefully in the coming days I'll have a chance to test her out...in the meantime is it difficult on everyone else's bike to push the secondary sheave up on the splines of the output shaft?...took me 15 minutes trying to get it installed...finally I just got it started then screwed the nut on and used a ratchet to turn it the rest of the way...it went on fairly easy then...

ASPENDELL ROVER wrote:

phewww, you know after a long hike, this bike kicks ass! All I know is with JBS set up and advice, its a blast to drive. I can't imagine how fun it will be with an engine...lol

Ya damned hippie...ya been blowin too many "bubbles" !!!  

I find it tricky getting the secondary on sometimes, other times it seems to slip right on.