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Lucky ! Very expensive now. Would be cheaper if I sent my sheave in.
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If you are going to do any mod to your Griz then Arnie's machined sheave and secondary spring is the only way to go, EPI clutch kit is a waste of money and time sorry to say, remember you only have 50hp to work with you just have to know where to put the power were its needed to make a gain, Coops mod 3 package does this for your Griz hands down, you also can add .5-.7mm shim for more bottom end with Coops machine sheave setup just take note of belt rub on your sheave covers, you will loose a bit top end with the extra shims, 7200km on my Griz with Coops mod 3 and purple spring with .5mm shim, glad I bought it and has worked flawless.
 

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2007 grizz 660 camo sold 2019 honda passport 2001 breeze 125
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Prob best move these guys on here and gals are the best techs u will find and real info they are great at spending our money (not a bash) i did shim mod spring had the boys do the shopping i got it all and they helped me with my first cvt service ever shim mod epi spring all sort of stuff i was paying a shop for with that said trust them they are greatest
 

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Prob best move these guys on here and gals are the best techs u will find and real info they are great at spending our money (not a bash) i did shim mod spring had the boys do the shopping i got it all and they helped me with my first cvt service ever shim mod epi spring all sort of stuff i was paying a shop for with that said trust them they are great an wouldnt tell ya fact
Exactly. We were all at the learning stage at one time.
Is the best way, be guided with knowledge, learn yourself, get good, and pay it forward. These forums are great for that.

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I priced out a new sheave from him and it’s close to $500 Canadian bit pricey for me right now, I don’t want to send my sheave in cause I don’t want any down time before winter, I rip weekends and after work during the week so.
I don't know how much more bottom end you want but I have a 2021 with 26 zillas and I pull a small trailer with 500 pounds of corn and I have plenty of snap, a couple of weeks ago while my wives kodiak was in the shop she rode with me on my grizzly with 80 lbs of corn on the front rack and her in front of me no trailer, and I just burped the throttle and front wheels came up... I said it's a little little different than yours huh... we have to go thru all kinds of terrain including muddy fields and I have plenty of low end grunt. I don't even have to put it in low just ride in drive. But good luck on whatever your trying to do..😉
 

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When raw low end torque matters. Rescuing my at the time girlfriend's Artic Cat 15 miles back in the bush. You really feel the load especially going up hills.

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Another aspect of a high pulley ratio from shim(s), machining or a narrow belt I haven't read in this thread is there is less strain put on the wet-clutch assembly at take-off near the engine engagement r.p.m. of the wet-clutch shoe springs.
This happens because torque is the engine power used to get a load moving (whether coming out of the hole hard during normal riding or pulling a heavy load as pictured above) and the higher ratio from c.v.t. mods. lets the engine r.p.m. increase more over the stock pulley ratio. This increase in engine r.p.m. at take-off from zero ground speed provides greater lock-up pressure sooner in the wet-clutch drum to reduce slipping between the shoes and the drum.
Does everyone need this? No.....or not in most daily riding situations but.....in the game of changing the pulley ratio just in case of need I learned I can work the system much harder when needed with great results.
To take this game of c.v.t. mods to the next level after shim/machining mods I learned the stock 660 secondary spring rate was less than needed so....after a few different springs I learned the E.P.I. purple spring was the best choice because I didn't want more spring rate which puts other parts in the drive-line at risk.
With the purple spring there is no slip during 99% of my time on the trail(s), but every now and then I can get the bike bound up and with to much throttle the belt can be heard lightly chirping inside the cover. It is in one of these situations I get out the winch cable to ride on. I feel if I had a heavier spring I might break an axle, then be stuck with a bigger problem.
Also I want to point out your best set-up depends greatly on the tire diameter you run. I feel the 26.5" tall true size is best for the Grizzlies c.v.t. system so take this as a guide only. This is based on my trail conditions which are not like some other members around the world.
As for expense, those of us that enjoy the higher ratios already know the expense :) so know when we recommend a mod the recommendation(s) comes from our riding experiences. These experiences may be varied, so for me the benefits are an easier machine to handle when out on the trail.
Around here a day ride can be well over a hundred miles which is a long way past the range of a stock machine's fuel capacity. In the stock configuration, to go this distance or more in a day with no access to a town (gas pump), the addition of an extra fuel tank is needed which then changes the balance of the machine. C.V.T. mods can greatly increase the range of a Grizzly on one tank of gas which I like.
A few years ago 3 other members of G.C. met me in my local area for a few days of riding. The first to arrive was here for a Y.O.L.O. trip and we had spent the previous 9 months planning for his arrival and spent his first two days here getting him use to the area trails and double checking his 700 c.v.t. set-up for our third long day out on the trails. Our goal that day was ride two Grizzlies 500 miles each without using a gas pump or fuel dump placed earlier. We had to carry everything we needed for the day from camp. We did 455 miles that day while relying on c.v.t. mods to raise the fuel range of a tank of gas by lowering the cruising engine r.p.m.
Then while gone that long day, the two others members met us in camp for 4 more spectacular days on the local trails, and over 7 days the first member to arrive and I had done 978 miles.
Having a well behaving machine was nice, so at the end of each day we could get ready for the next day out.
C.V.T. mods are not needed by all so let me point out to new members while going back through old threads, look for how many members remove c.v.t. and what those mods are and the reason for removal.
 

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Discussion Starter · #29 ·
Well installed the EPI clutch kit kept the 1.5mm shims in and I’m pretty impressed! Smooth clutch engagement and I’m roostering like crazy now when before I wasn’t so I’m pretty happy but still plan on doing the Mod #3
 
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