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Discussion Starter #1
Hi. I have a 2009 Grizzly 700 which is totally standard. Over time with use I have noticed the engine braking getting stronger and stronger. It is at a point now where it is too strong for my liking. I have researched on here and have gathered that this is because my V Belt has slowly worn over time. The rear tires are half worn as well which would be contributing to it I think.

I have checked the V Belt width, it is 31mm wide and still within spec. A new belt is 33mm.

What I want to ask is if I file down the collar inside the primary sheave 2mm and leave in the current 31mm belt, will this bring the gearing and engine braking back to the same amount as when the bike was new with a 33mm wide belt?

Is this the right way to go to mod the bike and achieve what I want? I could just put on a new belt but I thought this mod would be a cheaper way to do it. When the belt wears further then I can put on a new belt and shim the collar back to standard right?

Thanks for any help.
 

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Install a new belt is your best bet and is the correct way to get what you want. These clutches might be basic in operation, but they are still highly calibrated pieces. If you file down the collar you are doing something irreversible, and you will have farther things to replace when it doesn't work out......meaning more money.

The proper way to do what you want is to replace the belt.
 

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As said above, just replace the belt and be happy with it. Avoid doing anything you can not reverse
 

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Discussion Starter #4
I understand I can just change the belt but I want to know if filing the collar 1mm will give me the same result with the half worn belt and is it doable reliably? Does the face of the collar have to be 100% perfect or anything like that if shortening?

I can always buy a new collar as a spare part if I wanted to return it to normal. I'm guessing it would be a lot cheaper than a new belt.
 

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You can machine off a mm or 2. It does need to be true if not it would cause the camplate or the fixed sheave to wobble.
A new belt would be your best choice. It is going to need to replaced sometime. Worn 2mm it probably has some cracking.
Have service the secondary sheave?
Have you lost top end speed?
 

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Discussion Starter #7
You can machine off a mm or 2. It does need to be true if not it would cause the camplate or the fixed sheave to wobble.
A new belt would be your best choice. It is going to need to replaced sometime. Worn 2mm it probably has some cracking.
Have service the secondary sheave?
Have you lost top end speed?
No The secondary sheave has never been serviced since new. I didn't realise it had to be serviced. Can that cause excessive engine braking not being serviced? What is involved in that? I'll check the service manual as well.

I haven't checked if I have lost top speed.

Thanks..
 

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with an un-serviced clutch there could be a lot of different things going on that could contribute to your increased engine braking. and there probably are a lot of things combined that are all contributing.. not only to that, but contributing to other things as well that may not even be noticed. top speed, power, gas mileage...

you could have bad grease in your primary, and flat rollers which could be keeping you in a lower gear... and when you are letting off the throttle, its really slowing you down... same with the secondary....

basically, in your position, i think youve gone way longer than one should expect without servicing the cvt... so i would recommend a full service. checking seals, re-greasing secondary, checking weights for flat spots, re-greasing the primary, new belt.

its not that much work, and you can do it yourself if you are mechanically inclined. it will really freshen up your machine. lmk if you want to try it yourself. i can give you a whole bunch of info which may or may not be overwhelming..
 

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with an un-serviced clutch there could be a lot of different things going on that could contribute to your increased engine braking. and there probably are a lot of things combined that are all contributing.. not only to that, but contributing to other things as well that may not even be noticed. top speed, power, gas mileage...

you could have bad grease in your primary, and flat rollers which could be keeping you in a lower gear... and when you are letting off the throttle, its really slowing you down... same with the secondary....

basically, in your position, i think youve gone way longer than one should expect without servicing the cvt... so i would recommend a full service. checking seals, re-greasing secondary, checking weights for flat spots, re-greasing the primary, new belt.

its not that much work, and you can do it yourself if you are mechanically inclined. it will really freshen up your machine. lmk if you want to try it yourself. i can give you a whole bunch of info which may or may not be overwhelming..
I completely agree with this. Good information.
 

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Discussion Starter #10
with an un-serviced clutch there could be a lot of different things going on that could contribute to your increased engine braking. and there probably are a lot of things combined that are all contributing.. not only to that, but contributing to other things as well that may not even be noticed. top speed, power, gas mileage...

you could have bad grease in your primary, and flat rollers which could be keeping you in a lower gear... and when you are letting off the throttle, its really slowing you down... same with the secondary....

basically, in your position, i think youve gone way longer than one should expect without servicing the cvt... so i would recommend a full service. checking seals, re-greasing secondary, checking weights for flat spots, re-greasing the primary, new belt.

its not that much work, and you can do it yourself if you are mechanically inclined. it will really freshen up your machine. lmk if you want to try it yourself. i can give you a whole bunch of info which may or may not be overwhelming..

Sounds like very good information. Thankyou. My bike has only done 1000 miles so far if that helps.
I will do the servicing myself and I'm very interested in more information on the clutch servicing.
 

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Sounds like very good information. Thankyou. My bike has only done 1000 miles so far if that helps.
I will do the servicing myself and I'm very interested in more information on the clutch servicing.
hmm. now that is interesting... with only 1000 miles, there shouldnt be that much wear or tear on the cvt that it is causing any significant change to the engine braking...

you are about due for a cvt servicing, but i didnt do mine till it had about 2000 miles on it. it made a difference, certainly, but i didnt feel like it was necessarily overdue for the servicing.

im surprised your belt is worn too.

here is my go to post for people wanting to service their CVT, swap out parts, etc. yo may/may not need all the info depending on how far you need/want to tear into it.

here are some links i have saved from when i dug in there...
sheave holder:
http://www.grizzlycentral.com/forum/grizzly-engine-transmission/22654-diy-sheave-holder.html
servicing the secondary:
roughing up the sheave faces:
some info on getting to the wet clutch/one way, should you ever do that
Where is my Grizzly's wet clutch?
belt specs
Replacing Belt?
some torque values
clutch plans... whaddya think?

i already had dug into the primary, so i dont have a good vid on that removal... but here is a decent vid on greasing the primary(use oem grease, or a good brand like beltran)
imo, he uses a bit too much grease on the sliders..

here is a good video on the whole thing... its on a 450, but it gives the right idea.
this vid shows him using an impact on the primary. it also shows him using an impact to remove the secondary spring without compressing the nut. i wouldnt recommend that. its easy to use the front wheel to take some pressure off the threads. otherwise that spring could potentially strip the last thread on the nut/secondary. you need to compress it to get it back on anyways, so you might as well do it to take it off.

it also shows him running the machine with the primary cage off at the end of the video. i would also recommend against that.
common things people mess up on... make sure you dont use an impact to remove primary. secondary is ok.
hold the cam plate tight to the primary sheave during replacement. you dont want the weights to fall out of place
use torque specs to replace primary and secondary nuts
make sure you center the outer washer on the primary shaft so it doesnt pinch between the splines and the nut. also make sure you arent pinching the belt when tightening the primary nut.
 

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I have 1000 miles but high hours in comparison as I use the quad for farm work as well as riding. the belt is at 31mm.
That is a lot of wear for only 1000 miles the hours make no difference as the CVT doesn't rotate when idling.
You should use low gear when you are doing farm work. This will make the engine braking more pronounced but will be easier on the belt and the wet clutch.

Not servicing the secondary..If the secondary is gummed up it will not shift up and down as it should. If it is sticking in the lower gear ratio like first or what we northern backwooders call Granny gear. The engine braking will be more intense.
Engine braking kicks in when the wheel rpm is greater than the engine rpm.
Pull it apart clean everything and regrease with a good quality high temp waterproof wheel bearing grease.
The assembly grease that Yamaha spec's is like the the wax on a toilet wax ring. Great for assembling the parts but too stiff.
If you grease the primary as in the video about you will have more problems. If you must grease just use a 1/2 teaspoon on each roller channel.
 

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Not servicing the secondary..If the secondary is gummed up it will not shift up and down as it should.
A lot of air goes through the C.V.T. cover and in dusty conditions will cause the grease to thicken much sooner.
I go 1000 miles when riding alone or in the lead before replacing the C.V.T. grease, but when following others or in dust blowing conditions I check the grease after 2 or 3 hundred miles.
Also, the belt material worn from the belt contaminates the grease.
As you expressed no concern for take-off power or acceleration the belt wear may not be your concern and servicing should help the back-shift.

In theory shortening the collar lets the movable sheave ride closer to the fixed sheave but the end of the collar must be 90 degrees to the collar side or the movable sheave will not run turn, exactly perpendicular to the shaft. With each rotation of the shaft a variable pressure through the weights will be applies to the sheave and at 6000 rpm's can cause damage.
Yes 2 mm's from the belt and 2 mm's from the collar provides about the same ratio, but a narrower belt was more distortion so the ratio should be slightly different than stock.
If you replace the belt I recommend going with O.E.M. I tried two Dayco belts, 1 HPX and 1 XPX, and both together didn't last as long as your stock belt.
Let us know how this project works out.
 

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Discussion Starter #16
As you expressed no concern for take-off power or acceleration the belt wear may not be your concern and servicing should help the back-shift.

.

Take off power and acceleration is very good if not stronger than from new. From what I have read a worn/ narrower belt increases take off power.

I will definitely be giving the CVT a service before changing anything. Will get back with the results.

Thanks..
 

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Take off power and acceleration is very good if not stronger than from new. From what I have read a worn/ narrower belt increases take off power.

I will definitely be giving the CVT a service before changing anything. Will get back with the results.

Thanks..
I used the term shim equivalent for changes that act like shim and raise the pulley ratio, but are not from shim.
These can positive or negative numbers.
 

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Discussion Starter #18
Ok. I went for a ride today and can better explain the engine braking force. I can't really remember how strong it was when new but it cannot have been as strong as it is now as it throws me forward when I let off the throttle.

On a flat loose gravel surface doing 24mph and then letting off the throttle, the rear wheels don't lock but they slightly break traction as if the brake is on and I get that bouncing rear end like you do when you apply the rear brake.
Does this sound normal or excessive? Either way, it's too much for me so one way or another I want to make it less.
 

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When is the last time you checked the brake pads or serviced the brakes on the Grizz? Also, are you running any handguards? I had a problem with the rear brake not fully releasing with a set of handguards installed. Make sure your brakes at the handlebar are releasing when let off.
Keep the info coming, we'll figure this out. Also, did you service the CVT today before the ride?
 

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Great info here!! I can't stress enough how important it is to properly torque the primary and secondary nuts when reinstalling. MANY have learned the hard way, me included. Expensive damage can be caused but I got very lucky!
 
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