Belt deflection on RS sleds

[62crusr]

I'm trying to figure out if there is away to adjust the belt deflection or not on my RS Venture. I have an service manual but there is no mention of it. If I adjust the washers on my secondary to get the belt to sit at the correct height in the secondary the belt defection is inadequate (ie. the belt is too tight) and it causes the drive train to turn and will actually move the sled.

It appears the engine and jackshaft are in fixed positions on the same bulkhead so the only thing I can think of to increase deflection if there is adjustment that would allow the engine to swival clockwise when looking at it from the clutch side. I'm currently using an Ultimax3 belt which I thought I read was supposed to be a 1/4 inch longer than the Yamaha 8DN.

Another thing I've discovered is that if you pull the track by hand with the rear end lifted up there is a signficant difference in turning resistance with the belt on and then with it off . I think this is where the whole engine braking comes from. If you had more deflection I think you would lessen the braking effect and get more coasting. I could see this increasing gas mileage as well.

Any ideas?

 

[QCRider]

Have you checked the center to center distance between your clutches? It sounds like they may be too far apart...

 

[62crusr]

No I haven't. Since the distance isn't in the service manual maybe someone could measure their's and let me know. I will check mine tonight.

 

[Wilson]

The center to center distance is not adjustable on the RS sleds . The belt deflection is adjusted by removing or adding shims to the three bolts on the back side of the secondary clutch . I find that when I first install a new belt I have to remove them .After a couple thousand km I put them back .
There are no other adjustments for the belt as far as I know .

 

[QCRider]

Why are you not using the Yamaha belt?

 

[Wilson]

I always use the yamaha belt .But it squeels at idle for the first while
the dealer told me to take the shimms out and it worked .

 

[62crusr]

The main reason I changed to Ultimax3 was that my primary developed large deep grooves in it last year, so much so I had it changed under warranty. I attribute allot of it to the hardness of the Yamaha 8DN belt. Yes they last forever but from my experience at the expense of the primary. It also squealed excessively.

I have found the Ultimax3 to be a superior belt. The clutch wear is more or less gone, it slips noticeably less getting more power to the snow, no more squeal and it has shown very little wear after 2500km this season. Probably because it doesn't slip like the Yamaha belt.

I measured the center to center primary to second distance and it is approximate 10 5/8 inches. Has anyone else measured theirs?

I talked to mechanic at my dealer yesterday and he said the deflection via the secondary washers should be set to the track is just on the verge of but not spinning while up on the jack. He said not to worry about the height in the secondary as a mm or so in height doesn't make that much difference. He also confirmed the primary and secondary distance is not adjustable.

I also measured the circumference of the 3 belts that I had (one Yamaha and two Ultimax3) and found that they were all within about 1mm of each other. It was Hartman Inc. Yamaha Performance Specialists that claim the Ultimax3 was a 1/4 inch longer. Unfortunately this doesn't seem to be the case.

 

[CharlieAZ]

The center to center distance is not adjustable on the RS sleds . The belt deflection is adjusted by removing or adding shims to the three bolts on the back side of the secondary clutch . I find that when I first install a new belt I have to remove them .After a couple thousand km I put them back .
There are no other adjustments for the belt as far as I know .

Question related to this when I look at my secondary , how far down should belt be , should belt be even with the top of the secondary Sheave ?