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2003 Yamaha grizzly 660
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Discussion Starter · #1 ·
Hello everyone, I have a couple questions for you awesome grizzly owners.

1.Has anyone found a reliable & affordable 686 big bore combination that won’t cause the machine to over heat when going slow because I need a lot of off idle to mid rpm torque?

2.Does anyone know of a camshaft for the 660 grizzly that has a rough sounding idle similar to the 60’s Muscle cars & trucks?

3.Does anyone have any recommended & reliable long lasting clutch modifications for 27” & larger tires I’ve been wanting to get 29” outlaw tires or 28” outlaw 3 tires for a while now…..
 

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Cam shaft wont sound like a muscle car on a single cylinder. Have multiple big cams in my 843cc grizlzy and they sound like a stock motor

Lots of clutch set ups on these forems, trial and error
I would definitley install wet slugs in wet clutch weights for better durability
 

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2003 Yamaha grizzly 660
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15 Posts
Discussion Starter · #3 ·
Cam shaft wont sound like a muscle car on a single cylinder. Have multiple big cams in my 843cc grizlzy and they sound like a stock motor

Lots of clutch set ups on these forems, trial and error
I would definitley install wet slugs in wet clutch weights for better durability
Thank you for the advice I am a beginner in modifying grizzly 660’s
 

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2003 Yamaha grizzly 660
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Discussion Starter · #4 ·
A
Thank you for the advice I am a beginner in modifying grizzly 660’s
n
Thank you for the advice I am a beginner in modifying grizzly 660’s
Is there a good reliable & affordable clutch kit I could buy that can withstand heavy mud tires & plowing & if not what clutch modifications should I do? So I really want a lot more torque in the lower rpm’s good & useful advice is appreciated please & thank you 😁😁😁😁👍👍😁😁😁
 

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2003 Yamaha grizzly 660
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Discussion Starter · #5 ·
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n

Is there a good reliable & affordable clutch kit I could buy that can withstand heavy mud tires & plowing & if not what clutch modifications should I do? So I really want a lot more torque in the lower rpm’s good & useful advice is appreciated please & thank you 😁😁😁😁👍👍😁😁😁
Werner Williams you have had wonderful really helpful advice thank you
 

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2020 kodiak 450SE
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388 Posts
Don't waste money on a clutch kit. All you need to do is install some shims and run a stiffer secondary spring.
 

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2003 Yamaha grizzly 660
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Discussion Starter · #7 ·
Don't waste money on a clutch kit. All you need to do is install some shims and run a stiffer secondary spring.
Can you please explain where the shims would go & what they are & they do please & where does the secondary spring go? Also which spring would be recommended? & where does the secondary spring go? Thank you for your advice & saving me money 😁
 

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2014 Yamaha Grizzly 700 EPS
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Can you please explain where the shims would go & what they are & they do please & where does the secondary spring go? Also which spring would be recommended? & where does the secondary spring go? Thank you for your advice & saving me money 😁
In the Grizzly Talk forum, Grizzly Talk link, there is a FAQ thread stickied at the top. In that thread under General, there are 7 threads listed as good source information for understanding the Yamaha Utramatic CVT, how it works and how to safely modify to get a higher ratio for better low end. Those threads will answer a lot of your questions and are very good reference for when you may end up doing something similar. Read through those and also watch the Yamaha video to see how the Ultramatic functions... will help as you go through the information.
 

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2003 Yamaha grizzly 660
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Discussion Starter · #10 ·
In the Grizzly Talk forum, Grizzly Talk link, there is a FAQ thread stickied at the top. In that thread under General, there are 7 threads listed as good source information for understanding the Yamaha Utramatic CVT, how it works and how to safely modify to get a higher ratio for better low end. Those threads will answer a lot of your questions and are very good reference for when you may end up doing something similar. Read through those and also watch the Yamaha video to see how the Ultramatic functions... will help as you go through the information.
Thank you for the information 😁😁😁
 

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2020 kodiak 450SE
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388 Posts
Thank you for the information 😁😁😁
Yeah, read those threads, watch some videos on it. Good advice there.

Basically though... the shims go in between the primary clutch sheaves, causing the belt to ride deeper, lowering your cvt ratio. The secondary spring gets installed in the secondary clutch, an upgraded one will be stiffer and need more rpm to shift up. This will keep your motor higher in its torque curve, allowing it to turn big muddies easier
 

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2003 Yamaha grizzly 660
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Discussion Starter · #12 ·
Yeah, read those threads, watch some videos on it. Good advice there.

Basically though... the shims go in between the primary clutch sheaves, causing the belt to ride deeper, lowering your cvt ratio. The secondary spring gets installed in the secondary clutch, an upgraded one will be stiffer and need more rpm to shift up. This will keep your motor higher in its torque curve, allowing it to turn big muddies easier
Thank you for the amazingly awesome advice 😁😁😁😁
 
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