Clutch lateral travel & offset

[**sj**]

I’ll ad this
If your clutches are not hot then it’s time to look for binding issues.

good add....

soupy you doing a lot of off trail? when /what are the scenarios when you blow?

 

[jaydaniels]

I checked the secondary clutch total lateral travel of the sheave with the spring removed and got 1.02.

 

[Soupy]

Measuring driven clutch-to-belt parallelism continues to indicate that I need 2mm shim behind driven (giving 62.2mm offset) to be parallel at engagement. Unfortunately if I do this, the driven will be outward approx 2.5mm too far when shifted, according to my mockup with springs removed and belt installed. Mockup with no shim at full shift indicates my driven needs to move inward further still to be parallel. After removing the belt guard for a better look and seeing that the primary moves the belt laterally more than I realized after engagement, but prior to beginning to shift (my guess is .060-.080), I'm thinking I should try my setup with no shim behind the driven in hopes of being better alignment at speed.

This is with Thunder products orange sidewinder driven spring, 33/35 helix, adjustable weights and stock primary spring, engaging at 2800.

I understand that this contradicts adding a shim like most are recommending. If I've done something wrong or made a mistake, please let me know.

 

[**sj**]

I think you are referring to offset...parallelism is the two clutches remaining face parallel to each other...on this machine there shouldnt be a concern with this compared to the machine it replaced...

to get to a correct offset...you are saying removing a shim to go beyond 61mm ? Im not seeing that....if anything you should need two shims to get there or more?

 

[Soupy]

Correct but I'm basing my findings on placing a straightedge on the machined OD of the secondary and adjusting offset to make the secondary/straightedge & belt parallel. Problem is that measurement changes from engagement to shift out. I thought I'd try aiming more for parallel after shifting has started. It seems to me that because of how much the primary moves the belt over before it actually starts to shift, the secondary should be further inward as well. At full shift, my mockup indicates that the secondary needs to be even further inward than allowed with no shims used. So I guess that means an offset of around 58mm.

 

[snowbeast]

Measuring driven clutch-to-belt parallelism continues to indicate that I need 2mm shim behind driven (giving 62.2mm offset) to be parallel at engagement. Unfortunately if I do this, the driven will be outward approx 2.5mm too far when shifted, according to my mockup with springs removed and belt installed. Mockup with no shim at full shift indicates my driven needs to move inward further still to be parallel. After removing the belt guard for a better look and seeing that the primary moves the belt laterally more than I realized after engagement, but prior to beginning to shift (my guess is .060-.080), I'm thinking I should try my setup with no shim behind the driven in hopes of being better alignment at speed.

This is with Thunder products orange sidewinder driven spring, 33/35 helix, adjustable weights and stock primary spring, engaging at 2800.

I understand that this contradicts adding a shim like most are recommending. If I've done something wrong or made a mistake, please let me know.

When we reassembled my sled after crash last year,and checked all things to be as close as they may have come from dealer,we ended up not running any secondary jackshaft shim,and got the max offset up,and in 720 hard miles with 270 hp tune on stock 8jp belt,all was good,so try it w/out shim and see,who knows,you may luck out like we did last year.

 

[ClutchMaster]

Here’s the thing boys Yamaha clutch alignment specs are spot on. If you set the sheaves up to factory specifications you won’t have any belts bottoming out in the secondary and belt will run straight in the sheaves. You can’t really do a mock up and expect good results because you can’t simulate belts tension that high.

Everything affects everything. For instance what if your center to center is 5mm~10mm short?
How does this affect your offset you need to run?