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Grizzled
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Finally got my coop45 mod3 primary moveable sheave installed over the weekend. I was able to get a few pictures of it sitting next to an OEM primary moveable sheave for comparison. Bike only has 370 miles on it still and the belt looked like it was brand new, no wear. I counted beginning and final ratio however it did not end up where I would expect. I believe that may be because of the low miles on the belt... not exactly sure, just a guess as I did not measure the belt width.

OEM ratio - 2.45:1

Coop45 mod3 primary sheave with .5mm shim - 2.7:1

Coop45 mod3 primary sheave with .7mm shim - 2.95:1

I also installed my purple secondary spring. That did raise the belt up on secondary but I'm not getting case rub right now. There did not seem to be any difference on where the belt sat on the secondary between .5mm & .7mm of shim. I did not measure, only assessed by sight so maybe it did slightly raise with the added .2mm of shim.

I've not actually taken the bike out for some riding yet, it's only on my property so far. It does feel A LOT better and I'm looking forward to getting it out on some trails.


OEM Primary Moveable Sheave on the right.

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Very nice. Look forward to hearing how a trail ride goes putting it through it’s paces.
 

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Finally got my coop45 mod3 primary moveable sheave installed over the weekend. I was able to get a few pictures of it sitting next to an OEM primary moveable sheave for comparison. Bike only has 370 miles on it still and the belt looked like it was brand new, no wear. I counted beginning and final ratio however it did not end up where I would expect. I believe that may be because of the low miles on the belt... not exactly sure, just a guess as I did not measure the belt width.

OEM ratio - 2.45:1

Coop45 mod3 primary sheave with .5mm shim - 2.7:1

Coop45 mod3 primary sheave with .7mm shim - 2.95:1

I also installed my purple secondary spring. That did raise the belt up on secondary but I'm not getting case rub right now. There did not seem to be any difference on where the belt sat on the secondary between .5mm & .7mm of shim. I did not measure, only assessed by sight so maybe it did slightly raise with the added .2mm of shim.

I've not actually taken the bike out for some riding yet, it's only on my property so far. It does feel A LOT better and I'm looking forward to getting it out on some trails.


OEM Primary Moveable Sheave on the right.

View attachment 97619

View attachment 97620

View attachment 97621

View attachment 97622
I bet you next time you service your primary you will find your ratio to be 3.1:1 because the belt will finally be "settled".

That's has always been my observations with every clutch mod I've done....
 

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I also have Coop45 mod3 primary with the 5mm shim and the stock 18gram weights, purple spring in the secondary, I have found a difference when towing my trailer plus the mid range has improved also, I found these mods have made a improvement but i'm not sure what my final ratio is with my belt settled in now, I found the tuner from EHS and stock exhaust mod lets my 708 breath a lot better but again i'm not sure what the gain would be, maybe 2-3 hp at most on top but my engine seems to run a lot better and a lot cooler for sure.
 

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If you get a chance ride it for a hundred miles or so and recheck your ratio after the belt wears into the new angle. I would bet like other have said your ratio will change for the better. You should notice a immediate difference from before to now.
 

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Grizzled
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Discussion Starter #6
Yeah, I’m not concerned about it and feel as you guys do that it will settle in with some miles and I’ll see the ratio get slightly better.

Seeing the two sheaves side by side, I am impressed with the machining coop did. Really smooth, flat surface and constant angle up towards the collar. Can’t tell where the machining starts and stops. And I wanted to show that the edge thickness didn’t change. I do need to mention the coop sheave in the picture has about 1500-2000 miles on it from my other Grizzly.
 

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Yeah, I’m not concerned about it and feel as you guys do that it will settle in with some miles and I’ll see the ratio get slightly better.

Seeing the two sheaves side by side, I am impressed with the machining coop did. Really smooth, flat surface and constant angle up towards the collar. Can’t tell where the machining starts and stops. And I wanted to show that the edge thickness didn’t change. I do need to mention the coop sheave in the picture has about 1500-2000 miles on it from my other Grizzly.
Tell me about it!

Here's mine.....
 

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Tell me about it!

Here's mine.....
Vincent, From the looks of your machined sheave it looks like your belt is about a 1/2" from the seal hump???
 

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Vincent, From the looks of your machined sheave it looks like your belt is about a 1/2" from the seal hump???
This is how things looked when I first pull the cover off.
 

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This is how things looked when I first pull the cover off.
You can't probable go much more without wearing a hole in your cover. But if there is more room you try smaller diameter rollers and then use a cam plate mod. I am going to look at this on my Grizzly and see if I can get a lower than 3.1 to 1 ratio.
 

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You can't probable go much more without wearing a hole in your cover. But if there is more room you try smaller diameter rollers and then use a cam plate mod. I am going to look at this on my Grizzly and see if I can get a lower than 3.1 to 1 ratio.
I already rubbed my cover pritty good. I'm good with 3.1:1
 

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I already rubbed my cover pritty good. I'm good with 3.1:1
Did you happen to measure how far your belt was sticking out over the secondary when you took that pic??
 

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Grizzled
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This is odd. I look at @Vincent pictures and my belt was not that far out on the secondary.

The more I learn, the more I don’t know.
 

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This is odd. I look at @Vincent pictures and my belt was not that far out on the secondary.

The more I learn, the more I don’t know.
Belt length and width can affect how far a belt will stick out of the secondary but there is not much for optional belts. Machined sheave + shims can do it as well. You have to watch how far the belt sticks out of the secondary so you don't rub a hole in the cover.
 

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@Vincent pictures and my belt was not that far out on the secondary.


The more I learn, the more I don’t know.
That's normal, again your belt hasn't settled down to your final ratio yet.

With my old belt I had significant rub, but had 3.2:1 ratio!

With my used but fresher belt I'm at 3.1:1 with plenty of clearance because of my previous belt.
 

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You can't probable go much more without wearing a hole in your cover. But if there is more room you try smaller diameter rollers and then use a cam plate mod. I am going to look at this on my Grizzly and see if I can get a lower than 3.1 to 1 ratio.
Smaller weights will have a similar effect as shims or machining. It opens up the primary allowing the belt to travel deeper. These CVTs have a finite amount of belt travel. Limited by the primary collar and running out of the secondary.
Anyone that claims more than 3.4:1 is probably not counting accurately. 3.4 can't be achieved without using an aftermarket belt.

My 3:1 machined CVT has primary belt wear and secondary belt exposure similar to @Vincent.
 

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Smaller weights will have a similar effect as shims or machining. It opens up the primary allowing the belt to travel deeper. These CVTs have a finite amount of belt travel. Limited by the primary collar and running out of the secondary.
Anyone that claims more than 3.4:1 is probably not counting accurately. 3.4 can't be achieved without using an aftermarket belt.

My 3:1 machined CVT has primary belt wear and secondary belt exposure similar to @Vincent.
I'm confirming your post information is directed to those with a 550 or 700 c.v.t.
I say this because the 660 c.v.t. has more flexibility/forgiveness for higher pulley ratio than the 700/550 set-up. This is for a couple reason;
1) The pulley sheaves on the new machines have a different shape/contour near the center of axis changing the limit of how close the belt can ride to the collar. Then...
2) The cover on the 660's has a little more interior room/area, not much but enough so the belt can ride out of the secondary further before contacting the cover. And this is a guess, but the 660 cover may be thicker allowing more rubbing before a hole appears, again just a guess.

For those wanting to look for the highest ratio on a 700, there are a few things to be tried CAREFULLY!
I say this because I have you tube videos showing my 3.54 to 1 ratio I use on my 660, the system ran then the ratio counted so the belt is set into it's operating position.
It shows the belt placement at rest others need to pay attention to, as in my opinion, to little belt in the secondary will cause belt slip with maximum toque magnification at take-off.
Also I have a video uploaded showing a 3.75 to 1 ratio with the cover off on a 660. Not a big deal as I accidentally did this ratio while not paying attention with the camera in my hand. I say not a big deal because I never plan on running this very high ratio because I use stock axles with a purple spring and in 'MY OPINION' the 3.54 ratio with a purple spring is the limit for the stock axles for high torque. I learned how easy a stock axle can be broke with this c.v.t. set-up, a long way from the truck alone and don't want to go through that again.
I don't know if I could get the cover over the high est ratio, but it can be had on a 660 so......
For those with a 700 looking for the max there are a couple thongs I would try.
A) I would first install the primary without grease requiring the grease cover so the cage be installed for an operating system. Then with a COOP primary I would add slowly to see were the limit of ratio is determined by the amount of belt still in the secondary.
Again with not cover to find the highest possible operating ratio. Then I would focus on getting the cover on, and this is where the work comes in.
From memory (remember I am getting old so be easy) years ago others with 700's reported being able to reposition the c.v.t. as mounted to the engine case, loosening the bolts slightly to wiggle/jockey the cover back and up slightly for more room for the belt out of the secondary pulley. Maybe the inside cover half mounting holes can be opened/elongated .5 to 1 mm to help reposition the cover. Again I haven't done this myself, but these are things I would look into doing.
Then with the cover in the best place I would remove shim and start to slowly rub in the belt like with my 660.
You may not get to the ratio I have for the 660, you may find a limit from the circumference of the primary collar, but I would play with it to know what can be done.
Here is a 3.54 video with a stock belt;

then here is a video of what might be found during inspection. I was messing around and the belt was coming apart, then I installed too much shim with the different belt and got a surprisingly high ratio. I forgot while holding the camera the second belt was narrower than the broken belt being replaced, I had more shim in for one belt than the other. I use the ratio count as an indication the set-up is correct, so a wrong ratio and I start looking for why (the problem). (again I never rubbed in a belt for this 3.75 ratio for a 660)
 

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How can I get ahold of COOP? thinking about doing this mod and would like to talk with him?
 

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