clutch explosion

[907nytro]

i was wondering if anyone has had there secondary cluthe expode. i have a 2009 nytro with a mpi supercharger. my secondary inside sheath broke in half and destroyed both clutches.

 

[Turk]

I bet your were slipping the belt from not enuff secondary pretension like having too steep a helix.
Seen a few of em do it when they run too steep a helix & not enuff secondary preload.

 

[SharkAttak]

i was wondering if anyone has had there secondary cluthe expode. i have a 2009 nytro with a mpi supercharger. my secondary inside sheath broke in half and destroyed both clutches.

that is unreal, post a pic if you can

 

[907nytro]

here are pics

 

[Turk]

What were you running for a clutch set up?
How much boost?
What were your rpm,s at?

 

[907nytro]

i run stm weights, stock driven clutch wound tight, 12psi, 8700rpm.

 

[spray25]

i run stm weights, stock driven clutch wound tight, 12psi, 8700rpm.

Can you be more specific?

 

[907nytro]

DRIVE CLUTCH: STM ADJUSTABLE WEIGHTS, AT ABOUT 71 GRAMS. PINK YELLOW PINK SPRING. 15.6 ROLLERS.

DRIVEN CLUTCH: GREEN ARCTIC CAT SPRING, 157 PSI. 70 DEG WIND. 39 DEG HELIX.

 

[spray25]

Dang 70 degrees on a Cat green spring? You are a lot tougher than I am!! That spring with a 39 helix pretty much removes the possibility of not enough backshift and belt squeeze. I would tend to think way to much tension and side pressure may have bound adn broke the secondary?

 

[907nytro]

maybe. i hope it was a one time deal. because that hurts the pocket book. it is back together so we will see what happens.

 

[spray25]

I was just looking at your picture again and it looks like the secondary spring is black not green. Are you sure you had hte AC green spring in when it broke? THe primary spring appears to be G/W/G. I didn't think it was even possible to twist the green AC spring to 70. It's all I can do to get it to 40.

 

[907nytro]

i have the green spring now in my new clutches. it was a stock yamaha spring wound to 90 deg.