IMO Ted is right with the heat build theory.
It takes it's toll over time.
I also agree that heavier, more agressive weights stress the clutch castings over time. Add agressive traction products and ...YUCK!!
I blew a belt at 125 (true speed). The belt pieces (100s) had a feeling like they'd been cooked. It was an older belt from the previous year and "looked" good. Only took 2-3 pulls at 130-138 and BOOM! Sounded a howitzer was mounted under the hood.
The first thing I thought, was remembering reading on TY about a clutch that exploded and took out a sled. I was about to freak out. All before I was even close to stopping.
I was really happy when I open the hood and saw it was just a belt. Clutches looked fine...then!
About a month later 3 hairline cracks showed up on the inside of the primary (the last run of the year). That clutch is now in a land fill somewhere in Western Mass.
A brand new one is on for this year.
We "all" need to watch this issue closely running these high HP sleds.
Change belts (and bearings) more frequently, and keep a close eye on that clutch.
It could save your life.
OTIS RX
