Clutch confusion

[TravisFader]

Ok so a few questions for you smart guys out there. I have a 04 Viper and i dropped about 5 grams each weight in my primary getting ready for the mountains. This increased my engagement RPM from 4200 to 5000. Should not a lighter weight make my engagement RPM go down thus making it easier to turn the track in the mountains? Do i want my mountain clutch setup to engage at a high rpm or a low one? Soooo confused here. any help would be greatly appreciated.

 

[my mod]

Lighter Weight will make your engagement go up as it will take more RPM's to get enough pressure to squeeze the clutch spring.
Engagement should be lower, but you still have to stay in the power band of the engine.

 

[TravisFader]

Ok, i see, so would i want a lighter, or heavier wweight for higher elevations?

 

[Zar]

Lighter Weight will make your engagement go up as it will take more RPM's to get enough pressure to squeeze the clutch spring.
Engagement should be lower, but you still have to stay in the power band of the engine.

I agree with My Mod . With every gain of 1000 ft of elevation your engine loses 2-3 % HP . With the loses in power you have to compensate for bringing your engine closer to the power band and correct the shifting (for the loss in power) and not exceed your peak RPM of your motor at WOT ( wide open throttle ). Becareful at lower elevation with lighter weights that your motor does not exceed the peak RPM - it hard on the crank and pistons etc. Some motors are more sensitive to primary clutch weights that others. Good Luck

 

[TravisFader]

Thanks guys, so what id want is for my engagement rpm to be higher so im in a higher powerband when it first engages is what im gathering? I have another heavier set of weights for around here (Vegreville) which engages at 42, does 5000 seem like the right enagage rpm? what rpm does your mountain machine engage at?

 

[Zar]

Thanks guys, so what id want is for my engagement rpm to be higher so im in a higher powerband when it first engages is what im gathering? I have another heavier set of weights for around here (Vegreville) which engages at 42, does 5000 seem like the right enagage rpm? what rpm does your mountain machine engage at?

My 800 Cat engages at about 4200 RPM with mountian weights ( which is a bit low but not so harsh on the standing starts) . You would have to find another person with a Viper to make a fair comparision. Google the internet or talk to a dealer and even some shop manuals list engagement RPMs for certain stock setups. Make sure your belt is good condition (new or almost new) when you are comparing clutching details ( engagement, peak RPM, shifting etc)

 

[DaveB]

Typically, you would set your engagement RPM with the primary spring.....set you peak RPM with the weights. It's a balancing act. What were you trying to achieve with the reclutching? Going 5g lower per weight is a large jump.....you will likely increase your peak RPM by 500 to 800.

 

[TravisFader]

Scratch the 5 g difference i went from 49 g to 46.5. I went to totallyyamaha.com and they have a clutch comparison chart there. Seems that 5000 RPM for my triple is pretty good for what some of those guys have listed there for mtn riding. some engage as high as 5400. So really im gonna wait till i hit the mountain before i fiddle with it again and see how it goes. Thanks for the input guys. Yamaha weights are something i hate fiddling with.