Studroes144
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anyone have info on a real stiff preload primary spring? Running GWG with 2 shims (4mm total) and still can't get engagement high enough where I want it. This is a turbo with heavy weights. I'm using gates belt which is wider and 14.5mm rollers so those are working against me a bit but gotta think there's an aftermarket spring that can get my engagement up higher. Sled is moving at 25-2600, wanna get engagement in the 3500 range.
What's the belt to sheave clearance in Primary? Gates is wider than 8dn if I remember right. That would affect your engagement also.
Here is all the charts.
http://ty4stroke.com/threads/latest-primary-clutch-spring-specs.147870/
http://ty4stroke.com/threads/latest-primary-clutch-spring-specs.147870/
Studroes144
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Not sure on clearance, measured belt widths at one time but can't remember how much wider the gates was than the 8dn. Clearance I'm sure is pretty tight.
I run .015 clearance. Measured with a feeler guage.
If you want to try my 911 adjustable cover I can send it to you after this weekend which will be my last ride this season.
Studroes you should try that Sidewinder Gold spring those guys all hate! That might be ticket for you.
Studroes144
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I was thinking the same thing as you actually, I know a couple locals that have the springs actually..may hafta snag one up. Would be interesting to do the same vice test with one to see if it actually would bind. Either way it probably wouldn't bind in mine with the taller gearing..I don't plan on doing any 130+ mph runs anytime soon.
You know those flat weights are why your engagement is so low. Have you compared the Profile of the new OSP weights for Winder to the Magnaforce Viper weights?
Studroes144
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Haven't seen any first hand for the sidewinder, the osp viper weights that I have compared to the d&d magnaforce I feel are very similar. If I remember right the only difference was the magnaforce weights had a very slight bump on the heel, otherwise I think profile was exactly the same. The osp weights are definitely the reason for the real low engagement, with magnaforce weights I could get engagement up with just different springs, now with the stiff springs plus shims I still can't get it very high. It's good at 2500 and pulls hard right off stutter, just want it higher to get some more snap and see if it'll hold traction.
It's that little bump Studroes. Check that belt clearance and if it's tight try my 911 cover.
Studroes144
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Yup I'll check it out. Never split a yammi primary, are they similar to the cat primary where you can change shim sizes to adjust belt clearance? 911 cover would certainly be nice but if I can do it with a different shim it'll certainly be way more cost effective.
Yes. Can be shimmed. Try the cover first if needed so you don't waste time splitting primary.
Actually I could tell you. Just measure your clearance and I will duplicate it and see how much rpm it brings mine down. Should be close. I bet it's almost 200 rpm if it's tight vs loose easy.
200 probably won't be enough will it?
