Blowing belts

[Big_Phil]

My brothers nytro used to de laminate belts last year and early this year. Always while doing high speed runs. I think the secondary was warped or something. We switched secondaries from another Nytro that didnt have a belt problem, and its all good now. He is running a 5psi turbo now and he just put 2000kms on a belt with lots of drag racing and high speed runs. No more delamination.

 

[Mills]

Yes it could. I had suggested in an earlier reply to this thread that you may have a jack shaft bearing issue. I had this issue with an SXR years ago and it turned out to be the jack shaft bearing on the clutch side.

 

[actionjack]

Well, I did a thorough cleaning, replaced sliders in secondary, both bushing in secondary (new ones are really no tighter than old ones), everything in primary is good. Had dealer check alignment, defection motor mounts all good. Put new belt on, and got 10km and a bunch of threads came out of outboard side of belt, clutches too hot to put hand on for more than 3-4 seconds, belt very hot. there is a vibration coming from the front end, worse the faster I go. The jackshaft bearing feels rough/squeaks when rolled back and forth with belt off. Took secondary off and when I push and pull on shaft there is a tiny bit of play between inner and outer races of jackshaft bearing but no up/down play, pulled out seal and grease is brown. Could this tiny bit play cause some sort of vibration at high speed, which is causing the belt to slip and heat up then delaminate. While accelerating it feels to be slipping. I am going to change the bearing regardless but am just wondering if this theory sounds plausible. How often should the chaincase bearings be changed, 14000km on the sled, case oil changed yearly since new.

Yeah that sounds like problem found for sure. Squeaking bearing, free play, and vibration. Bingo.

 

[musselmark]

I just got it all back together and took it for a ride, way smoother, doesn't slip as it used too, but after 5 minutes of driving, nothing crazy, I popped off the cover and felt clutches/belt and they are pretty warm, belt feels warmer than clutches, not too hot to keep my hand on but pretty warm. Is this normal?

 

[blueironranger]

I just got it all back together and took it for a ride, way smoother, doesn't slip as it used too, but after 5 minutes of driving, nothing crazy, I popped off the cover and felt clutches/belt and they are pretty warm, belt feels warmer than clutches, not too hot to keep my hand on but pretty warm. Is this normal?

if you can keep your hands on the clutch I consider that cool, warm for me has always been the 5 second rule, and Hot is when I have to immediately remove my hand from the clutch face. That me but I know a lot of other guys that follow the same rules. This is after about 10 minutes of riding or 3-4 ZERO to WOT pulls.

 

[Mills]

sounds like problem solved and temps on belt/clutches is normal now.

 

[musselmark]

I just put 1000 hard km on new belt in Quebec and all is now good. I changed the jackshaft bearing, then took it to dealer and the first thing the mechanic saw was a gap in the plastic forward of the primary and towards the inside which he thought could have been letting snow in. He caulked it with silicone and also added shims to the primary buttons and new o-rings to the roller bolts which really quieted down the rattle.