My son smoked the belt yesterday helping me take down a tree.

I took the cover off and inspected the belt. It definitely has a wear on it which causes the UTV to hesitate off idle. Once the RPM's are up and the UTV is rolling it is fine.
This is the Uforce 500 dry clutch setup.

My question to the clutch experts here is that upon inspection I found a groove on the primary clutch plate exterior side (none on the interior / engine side) and a roller mark on the belt. Is this by design?
No metal shavings were found inside the cover.

[2015 Z Force 800 53/Trail EPS]

The roller mark, yes, that's where the belt rests when not engaged but the mark on the sheave is from either engagement or from slipping. I also see more gap or gauge between the sheave and belt then I would have expected which on others would indicate a very warn belt or something allowing the two parts to move apart more. Probably just the belt though and probably can't see the whole thing so... I also see what looks to be grease from the bearing on the spindle. If so, it will or already has gotten on the belt and that may be your biggest problem.

The roller mark, yes, that's where the belt rests when not engaged but the mark on the sheave is from either engagement or from slipping. I also see more gap or gauge between the sheave and belt then I would have expected which on others would indicate a very warn belt or something allowing the two parts to move apart more. Probably just the belt though and probably can't see the whole thing so... I also see what looks to be grease from the bearing on the spindle. If so, it will or already has gotten on the belt and that may be your biggest problem.

Thanks for the quick reply. The extra gap you see is because I have the secondary open with a bolt. I measured the belt to be 35 mm so within spec. My concern was the shaved part that extends from being parallel with the roller inwards as though it was machined that way. In essence the belt should not ride in that area?

BTW, the UTV only has 80 miles total on it.

edit: Found a good picture in the service manual. There definitely is a machined groove in the sheave so all is good. just need a new belt.

Something you may want to consider is when to run low range. Sustained low mph will cause a lot wear on the clutch sheave because the belt is running low. I can explain if you want to be bored  It will kill the drive belt as well 

I've found 30kmph or less, run in low range.

Something you may want to consider is when to run low range. Sustained low mph will cause a lot wear on the clutch sheave because the belt is running low. I can explain if you want to be bored  It will kill the drive belt as well 

I've found 30kmph or less, run in low range.

I have been considering running in low range but the higher RPM's and noise bother me. May simply have to get used to it.

I was surprised at how quickly that belt was damaged. Just a few seconds of being anchored by the tree and blue smoke was being vented by the CVT. Certainly not impressed by this dry clutch.
This is something I not once encountered with my former Yamaha Grizzly 660.

Looks like I will have to baby this machine...

Any CVT dry or wet will smoke the belt in seconds. It's operator induced, not intentional by any means. You need to engage the clutch & move.

Many think it's like our automatic transmission in the vehicles we drive, we can sit on a hill & hold the vehicle. Not so with our CVT's we burn the belt.

You do not have to baby the machine, you have to operate appropriately. Get used to a little higher rpm & noise, it's built for it.

Any CVT dry or wet will smoke the belt in seconds. It's operator induced, not intentional by any means. You need to engage the clutch & move.

Many think it's like our automatic transmission in the vehicles we drive, we can sit on a hill & hold the vehicle. Not so with our CVT's we burn the belt.

You do not have to baby the machine, you have to operate appropriately. Get used to a little higher rpm & noise, it's built for it.

This is my understanding of how wet versus dry clutches work. Information taken from another forum.
It appears that a wet clutch will slip before the belt does when put under heavy load if I read this right thus less wear on the belt?

http://www.rhinoforums.net/engine/41204-wet-dry-clutches-im-new-sorry.html

"A wet clutch engages in the motor as stated. There is a clutch between the primary and the motor inside the oil (thus wet comes in). The primary has no springs, but rather roller weights. And as RPM climb, it engages, then it turns the primary, and the roller weights are thrown to the outside by centrifugal force, and they move along an angled ramp. The farther from the center, the more narrow the ramp, and thus the primary sheave starts closing, and the bike upshifts. The advantage of this setup is, adding stall doesnt become jerky, long clutch life, smooth engagement, and constant belt tension. And you should never slip the belt if its clean and dry. Since the wet clutch should slip before the belt does. But it cant hold a ton of power. After a certain point, you are gonna spin the clutch. Now if you dont change the motor, you shouldnt have an issue with the 660, or 700 (686) motors. Maybe if you do like a 907 kit or something, but for the most part, its good to go with the stock block. You also cant run any kind of oil you want with this setup, it must be wet clutch compliant (friction modifier), or the clutch will slip more, and wear it out, and performance is hindered.

A dry clutch is directly bolted to the crank, and has a primary spring, and fly weights. As the RPM build, the fly weights are pressed against the primary sheave, and fight against the spring. The spring has a snap action. The primary spins slowly, and will eventually overtake the spring snap action, and slam shut on the belt, and starting the bike to move forward. As the RPM build, the fly weights are pressing against the sheave, causing it to close, and the bike upshifts.

The advantage of the dry clutch (snowmobile style) is that it can hold a lot more power. Its harder to tune, and almost impossible to tune at home with mods. You need to buy new flyweights. Adding stall makes engagement jerky. And adding stall shortens belt life substantually. This is due to the fact that the belt sits idle on the primary as it spins (no tension, so it just slips on the inside of the belt), and it slams shut and starts moving the belt. If there is too much restriction on the tires, you will slip the belt. And as you engage and disengage its constantly slamming on the belt, and slipping a bit as it gets dirty or dusty, and it will glaze the outer edge, making it slip easier and easier, till the belt is chewed. So stall isnt a good thing with these clutches. But they can hold more power, so its popular among the boys who run big power. Till a certain point, then they go with a gear setup instead of a belt. But you can run any motor oil you want, sicne there is no wet clutch, so feel free to run that $18 a quart full synthetic that race cars use.

In both cases the secondary springs, help fight the upshift, and help backshift. In dry clutch setups a helix is involved to aid in the back shift setup

Here is a general breakdown of quads that use each clutch stock.

Dry Clutch:
Can-am
Last gen Popos
Kawi
Wet Clutch:
Suzuki KQ
Yami
Polaris XP models
AC (same as the KQs really)"

That's a ton of information  I agree with some of it......not a lot. Your post suggests the 800 ZF should be dry  it's wet 

Calibration is key. My experience is more sled which is dry clutch, I prefer very smooth engagement that you can walk beside. Very gentle easy throttle inputs....smooth.

The secondary clutch or driven is torque sensing, it fights nothing. I'ts purpose is to sense torque either direction allowing a up shift or a back shift. Calibration is how hard it clamps the belt & the speed of up or back shift. All independent of one another the black art becomes the combination of how it all works together....drive clutch....power & load.

Back to your issue, a spinning sheave against a stationary belt = smoke & a damaged belt. The load you had would not allow the belt to turn, would low range have helped?   Maybe, maybe not, dry clutch or wet would have probably the same end result.....the unit could not move.

Having spent time in both 500 & 800's, stock to stock clutching they are both a very good compromise for all the conditions they will see. Can it be better....always....it becomes more rider condition specific.

Sorry for the long post 

That's a ton of information  I agree with some of it......not a lot. Your post suggests the 800 ZF should be dry  it's wet 


Back to your issue, a spinning sheave against a stationary belt = smoke & a damaged belt. The load you had would not allow the belt to turn, would low range have helped?   Maybe, maybe not, dry clutch or wet would have probably the same end result.....the unit could not move.

Having spent time in both 500 & 800's, stock to stock clutching they are both a very good compromise for all the conditions they will see. Can it be better....always....it becomes more rider condition specific.

Sorry for the long post 

I did not suggest anything in regards to the 800 ZF as my Uforce is a 500 with a dry clutch. The UTV was in reverse when the belt smoked and was pulling / guiding a tree down when it happened. I will chalk it up to driver inexperience as my son was in charge of making sure the tree did not hit the house (it did not  and I was on the chainsaw.

Looks like a new belt will make it all good again!
I ordered a Dayco yesterday. Half the price of the cfmoto belt.

In my experience never pull hard in reverse I have had three separate occasions where pulling hard with a cvt in reverse smoking a belt. My old belt started squealin in reverse pulling hard but I turned around and it pulled the at right out. Also have a buddy buy a brand new brute Force 3 hrs on it he smoked the belt ripped it two pulling in reverse trying to pull a guy outa the creek. Also watched brand new cam am 450 outlander smoke a belt pulling a stump out. I can't say why it's like that but from what I have seen I won't ever pull anything out in reverse just my two cents.

Your post suggests the 800 ZF should be dry  it's wet 


Back to your issue, a spinning sheave against a stationary belt = smoke & a damaged belt.

I did not suggest anything in regards to the 800 ZF as my Uforce is a 500 with a dry clutch. T

I brought up the ZFORCE 800 as a reference to your article about dry vs wet  It suggest higher power should be dry which is the opposite how CFMOTO builds their product. They use wet in the 800 V Twins, including the UFORCE 800.

With either clutch set up wet or dry if you engage the clutch & the belt does not rotate because it can't or you don't throttle enough.......the belt is doomed to failure.

Fully understand how fallen the tree as you did smoked the belt, with a CVT it's easy to hold some tension.....the belt cannot turn = smoke 

Ok, I got the belt today and a bolt to separate the secondary sheave tension. Unable to slip the belt off.
Do I need all these special tools in order to remove the primary / secondary drives and finally replace the belt?
What kind of a shit show have I gotten myself into....

[2015 Z Force 800 53/Trail EPS]

Looks like they did the same on these as they did on the 800s, made it so you have to remove the secondary to get the belt past the case. Just need a spanner or something to hold the secondary while R&R-ing the retainer. Not sure if you will actually need to remove the primary but it shoes the spanner for it in the pics...probably fits the secondary too. This is why I would never want to do a belt change on the trail with one of these.

OK, I was able to remove the primary front sheave (nice to find out the nut and bolt are left hand thread.. 
The old belt slipped out and was able to install the new one.

My dilemma now is re-installing the sheave while trying to compress the heavy spring and aligning things up. I do not have the "special tool". Any tips or trick on getting this done?

Isn't there is tapped hole in the secondary, M6. Take a long bolt and thread it in there to open it up to take tension off the belt.