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Discussion Starter #1
So I installed a jbs sheave with a purple spring and 15g weights and it ripped but couldn't wheelie anymore, installed 18g's weight and the wheelies are back. Yay. Also when I got the sheave I used belray marine grease since the yamaha stuff is pricey and was recommended by my local powersports shop.... bad idea, all the grease ended up on the sides of the sheave and none on the weights which started flat spotting, so when the 18g's I went with the yamaha ultramatic.
 

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Discussion Starter #2
Also found my clutch clover had some weird marks in it. I understand they are from the belt but not sure how it made them.
 

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Discussion Starter #3
I also tried shims with the jbs and it will take up to a 1mm before the primary will rub on the cage. It didn't seem that much better so I lowered to .5 to give a little more clearance. It doesn't rub with the 1mm in, it but its close. Also I might try the original stock spring in it as I might not need the purple spring with only the 26 zillas on it and will report back. So far I'm pleased with my findings and hope this helps some of you guys.
 

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It's well known that the weights have to be a closer to stock grams to wheelie.
The grease collected on the outer edge of the primary is normal. Centrifugal force slings it out there.
Never saw a case marked like that. Usually it is more of a scrape. Looks like it was melted in?
With the machining and the shims you will probably need to stay with the purple spring. It also depends on you riding style.
 
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It's well known that the weights have to be a closer to stock grams to wheelie.
The grease collected on the outer edge of the primary is normal. Centrifugal force slings it out there.
Never saw a case marked like that. Usually it is more of a scrape. Looks like it was melted in?
With the machining and the shims you will probably need to stay with the purple spring. It also depends on you riding style.
x2 to this information.
 

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those marks on the cover r usually from belt height too high is your belt height above the sec clutch just watch how high it goes will wear through
 

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Discussion Starter #9
I understand the belt being too high in the secondary would cause belt rub but it only sits about 2mm above the secondary or one belt tooth. My ratio is about 2.7 to 1. But those lines are perpendicular to the belt it just doesn't make sense. Thanks for the replies though.
 

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A jbs sheave + .5mm is only 2.7:1?
That doesn't seem like much for the money
 

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Discussion Starter #11
I don't know about ratios I just know it rips off the line and up to 65 and that's good enough for me.
 

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Discussion Starter #12
What do most people see with a jbs sheave? Maybe I'll compare it to the stock one and see how much I gained. Clutching is sort of addictive...
 

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The slider weight can be a problem. Because of their shape they don't drop down completely in the channel. I believe I see that in your picture. They need to be sanded off to get a lower ratio.
 

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Discussion Starter #14
The cam plate sits right on the sheave I don't think it can go any lower, also jbs mills down the weight channels for a lower starting position. I still have my stock sheave so I'll compare it next time I tear into it.
 

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my cover is the same way never appeared until I started clutching as well I have had my belt high enough that u could see the thread of belt on the side above the secondary,
 

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does the overdrive weight alone make for more top speed or does the clutch need to be machined for more movement?
 
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