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Belt life

A
Jan 30, 2011
313
104
43
Palmer AK
I blew a belt at 1100 miles. I figure not bad. I was racing down a 3 mile stretch of groomed trail, throttle to the bar for 30 seconds and bam a shotgun went off under my hood. I was thinking clutch spring or belt. Looked at the mess of spaghetti around the primary and cut it out with my swiss army knife. Amazing how little pieces form from from the belt at 8000 rpm. No other damaged observed. Put a new on on and away we went, had some deflection screetch for a bit at idle but it quit as I was getting ready to adjust it.

A few things/ questions I noticed last two rides:

After it blew the main was hot, I had to let it cool before I changed the belt.
The rest of the day it was fine, so belt alignment issues create heat?

The uptake on power was down for the bottom end, I figured snow conditions but am thinking belt wear. The new belt made me feel like she was jumping out of the snow again. I admit I was a bit easier on it due to the lack of a second spare. But I did have a few wide open runs, carving day not climbing day.

The clutch was clunking as it engaged, It also was sluggish shifting into low gear and out of low gear as I deaccelerated slowly. After the new belt it has quit. I am thinking deflection, am I wrong?

Thanks

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O

Oregonsledder

Well-known member
Jan 27, 2009
992
815
93
Bend Oregon
I blew a belt at 1100 miles. I figure not bad. I was racing down a 3 mile stretch of groomed trail, throttle to the bar for 30 seconds and bam a shotgun went off under my hood. I was thinking clutch spring or belt. Looked at the mess of spaghetti around the primary and cut it out with my swiss army knife. Amazing how little pieces form from from the belt at 8000 rpm. No other damaged observed. Put a new on on and away we went, had some deflection screetch for a bit at idle but it quit as I was getting ready to adjust it.

A few things/ questions I noticed last two rides:

After it blew the main was hot, I had to let it cool before I changed the belt.
The rest of the day it was fine, so belt alignment issues create heat?

The uptake on power was down for the bottom end, I figured snow conditions but am thinking belt wear. The new belt made me feel like she was jumping out of the snow again. I admit I was a bit easier on it due to the lack of a second spare. But I did have a few wide open runs, carving day not climbing day.

The clutch was clunking as it engaged, It also was sluggish shifting into low gear and out of low gear as I deaccelerated slowly. After the new belt it has quit. I am thinking deflection, am I wrong?

Thanks

If you want top performance out of your clutches you need to clean both clutches and de-glaze and clean the belt every 3 or 400 miles, and I mean clean... remove clutches, put them in a sink of hot soapy water and scrub them good with scotch brite. If you stay on top of this and keep the belt adjusted to spec, you will maintain optimum performance and get better wear out of the clutches and belt.
 

winter brew

Premium Member
Lifetime Membership
Nov 26, 2007
10,016
4,332
113
56
LakeTapps, Wa.
Heat is from slippage which is mainly from calibration. Alignment not so much.
The long full throttle/full shift pull puts a lot of strain on a belt, especially on a mountain sled with a shallow helix which puts even more squeeze on the belt....and when the belt gets to the bottom of the secondary and has no where to go, they will often come apart....a new belt might have failed too. If you do this often (go fast), consider gearing taller to keep the belt from bottoming or riding out of the primary. :face-icon-small-win
 

sled_guy

Well-known member
Premium Member
Jul 5, 2001
3,566
843
113
Riverton, Utah
The other thing that happens is when you are making a full high speed run and back off the throttle the clutches actually upshift. If you are close to full shiftout that can often cause the belt to over shift the clutches and they don't survive that.

sled_guy
 
A
Jan 30, 2011
313
104
43
Palmer AK
The other thing that happens is when you are making a full high speed run and back off the throttle the clutches actually upshift. If you are close to full shiftout that can often cause the belt to over shift the clutches and they don't survive that.

sled_guy

I have heard that that happens, we discussed it on the ride home. I was full out squeezing the $hit out of the go juice and BAM! We decided it was more likely miles and/ or the stress of an high speed run.

I guess I need to get a Rush for those kinds of runs! Heck I need at least 4 sleds in my barn now if I am going to be happy.

PRO, Rush, SWT and something for the wife:face-icon-small-hap
 
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