I appreciate your input...ill give it a shot and report back. If anyone else has any ideas on things to check it would be great!
Nytro belt issues please help
- Thread starter justinkredible56
- Start date
A
acutah
Well-known member
Wow...it sounds like you have done about everything. I think you need to start eliminating components. Do you have a friend with a Nytro? It could be as simple as you have a clutch that is out of balance. Take his clutch swap weights etc. and go ride. See what happens. It could be a simple fix.
Probably a long shot but is your track too tight? Is it aligned properly? The A20 is going to hook up way better than the Mav. I lost some track speed on firmer snow with mine. But not that much. (apex)
I also switched to Carlisle belts.
Just a thought, sounds like you have checked about everything else.
ETA: With Yamaha belts I always had "belt fuzz", are you destroying the belts? Or just getting "fuzz" ??
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Track tension is about 2 inches from the rails with no weight on the track so should be good. The belt starts to fray and produce the fuzz your talking about but then all of the chords come out. It's not just one side it's both sides of the belt also.
I would agree with this. You are fairly heavy so the 18t should help. I have over 800 miles on my original belt. About half of those miles are under boost and have never had any belt issues. I am pretty light (about 180 in full gear) so I can't really give a fair comparison but I hope you get it taken care of. Nytros aren't normally belt eaters.
Update: Finally got to ride this weekend after all of my extra precautions listed above. There is absolutely no improvement in belt life I could smell it all day. The belt is broken in and installed in the correct rotational direction. I had to sit around while everyone else was playing to let my clutches cool. The snow conditions had about 6 inches on top of a very hard base. I don't see any way possible for the snow to enter the engine compartment.
I guess my only next step is to buy a 18t sprocket...I hate the idea of throwing more money at a problem when it should work as is but a 40 dollar sprocket is better than the 350+ I've spent on belts already this season!
Anybody want to trade a 19t top sprocket for an 18t?
I guess my only next step is to buy a 18t sprocket...I hate the idea of throwing more money at a problem when it should work as is but a 40 dollar sprocket is better than the 350+ I've spent on belts already this season!
Anybody want to trade a 19t top sprocket for an 18t?
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I would suggest you pull all the stuff (tape, etc) off you did to enclose the cluches. It sounds like it's really a combination of stuff but definately your overheating the belts. I'd settle for a little snow once in awhile vs. constant high temps... Have you looked into any kind of Frog Skinz or some other vent covers that allow cooling but no snow ingress??
Are you leaving any rubber on the clutches ? If so where, Top, bottom, middle on primary and secondary ? Where is the belt riding in the primary ?
Just by looking at the clutching to me it seems like you need a stiffer secondary spring. You will also need more weight if you go to a stiffer secondary to overcome the stiffer spring.
Can you tell us what RPM you are seeing at WOT ?
If your slipping the belt it is either a clutching issue or possibly snow. My guess is the clutching. Your a heavier guy and need to clutch for it.
Which sled is this ? A 2009 Nytro MTX with a 162 ? and AAEN pipe correct ?
One thing i do notice is your weights seem very light. A stock Apex weight 8FS is 65 grams empty. Granted you are running a shallow helix with a soft spring but still something to look at. I'm guessing your belt isn't riding very high in the primary.
Answer these questions and maybe we can figure it out. The problem here is your running a stock Nytro with a pipe and most guys here are in the 200+ power range with turbo kits. If it was a turbo you would be figured out LOL.
Just by looking at the clutching to me it seems like you need a stiffer secondary spring. You will also need more weight if you go to a stiffer secondary to overcome the stiffer spring.
Can you tell us what RPM you are seeing at WOT ?
If your slipping the belt it is either a clutching issue or possibly snow. My guess is the clutching. Your a heavier guy and need to clutch for it.
Which sled is this ? A 2009 Nytro MTX with a 162 ? and AAEN pipe correct ?
One thing i do notice is your weights seem very light. A stock Apex weight 8FS is 65 grams empty. Granted you are running a shallow helix with a soft spring but still something to look at. I'm guessing your belt isn't riding very high in the primary.
Answer these questions and maybe we can figure it out. The problem here is your running a stock Nytro with a pipe and most guys here are in the 200+ power range with turbo kits. If it was a turbo you would be figured out LOL.
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This is a pic of my old Nytro. It was not a turbo sled. I ran a Cat yellow in the secondary set at 0 1 ie 10 degrees. For primary weights I ran Heavy hitters with the max size screw in the heel of the weight. I then loaded up the middle with the heavy steel screws and washers then just tuned the tip to get the rpms to 8800. Then sled had an Excell Vector header with a single pipe on it and was lightened by about 70 lbs. I doubt it made 155hp but it might have (take those after market HP claims with a grain of salt, plus they're always at sea level), anyways it ran very strong for a stock motored Nytro. It had a 156 CE 2.5 15 and I ran 19 40 gearing. I never blew 1 belt on that sled in 2500 kms, mind you I'm not 310 lbs but still. Get yourself a set of adjustable clutch weights Heavy hitters or Supertips or Dalton but something, use 14.5 mm rollers and go from there. If you try this and try that you'll be dickin around all year with other guys setups that aren't right for you. Put in the Cat yellow load up the bottom of the primary weights then tune the WOT rpms with the tip adjustments. Do some hard pulls and stop right away and feel your clutches if 1 is hotter than the other the hot one is slipping. You should be seeing close to 40 mph track speed. The only thing I can't rememer for sure is the primary spring. I used either a BWB of a GWG but I'm just guessing anyway if your primary gets hotter than your secondary you'll need to up the primary spring rate.
M5
PS If you see someone riding this sled kick them in the balls for me cause it was stolen last season.
M5
PS If you see someone riding this sled kick them in the balls for me cause it was stolen last season.
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I completely agree with you, I don't feel like the snow is actually getting on the belt because I can never hear the belt slip like you normally would when snow is sprayed on them. It's just a constant heat issue due from slippage and enclosing everything proved that. I'm thinking a vent kit would actually help my issue but it's not going to solve it.
I am working on getting some material comparable to the SLP Flo-rite mesh and putting it on my vents. I think this will help out a bunch. As for the tape it's coming off today.
Are you leaving any rubber on the clutches ? If so where, Top, bottom, middle on primary and secondary ? Where is the belt riding in the primary ?
I took some pictures of them for you.
Just by looking at the clutching to me it seems like you need a stiffer secondary spring. You will also need more weight if you go to a stiffer secondary to overcome the stiffer spring.
What would you recommend? I have heard a lot of people recommend the Arctic Cat Yellow spring not just for my application but for nytro's in general
Can you tell us what RPM you are seeing at WOT ?
I have adjusted the rivets in the weights to achieve 8900 on the trail and 85-8600 on a pull in bottomless powder.
If your slipping the belt it is either a clutching issue or possibly snow. My guess is the clutching. Your a heavier guy and need to clutch for it.
I think after the duct tape experiment that your right...it's not snow getting in. As for clutching for my weight when I paid Hartman Inc. for my clutch kit it was supposed to be built for my weight/elevation/and track size.
Which sled is this ? A 2009 Nytro MTX with a 162 ? and AAEN pipe correct ?
Yup that's it but it' has a AAEN header on it as well. I figure it's best to be specific in this situation.
One thing i do notice is your weights seem very light. A stock Apex weight 8FS is 65 grams empty. Granted you are running a shallow helix with a soft spring but still something to look at. I'm guessing your belt isn't riding very high in the primary.
Judging by the pictures I would have to agree with you 100%, but my RPM's are within spec so I figured it was just because of the smaller rollers I have.
Answer these questions and maybe we can figure it out. The problem here is your running a stock Nytro with a pipe and most guys here are in the 200+ power range with turbo kits. If it was a turbo you would be figured out LOL.
Well I will eventually have a turbo kit...I pay my own way through school so Housing/Tuition/Books/Food gets HELLA expensive but when I graduate I'm going to join the cool kids club!
Also included in the pictures is my belt after the first ride once it had been broken in.
M5 with the help you've given me throughout my time of owning the nytro, I'll tackle that M**** F***** and haul him across the border and let you do what you want with him!
As for my clutching issue. I initially bought the kit so I wouldn't have to do all of this. Fix it once and never look back. It seems it kind of did the opposite. I agree with not dicking around on different parts but I can't afford to go out and purchase a whole new set of different weights. But if that's the ONLY way to fix this then I'll have to save up. The cost of the weights (if fixes the problem) should offset the cost of the belts I'm burning at this rate by a large margin....
The secondary spring that is in it is the one that Hartman Inc. sent to me to go along with the rest of my complete custom clutch kit. The kit is supposed to be designed for my weight/elevation/track size/riding type/and performance upgrades.
I have the secondary spring wound to 100* currently and have my weight's adjusted to get optimum rpm at that pre-tension setting. I am considering ordering a yellow arctic cat spring.
For sure the reason you're not getting any track speed is the primary is not shifting out after looking at your pictures. You'll still see 8900 rpm or whatever but the belt needs to travel further up the clutch sheave. Here begins the problem with clutching, it could be caused by too light of a primary weight, too stiff of a primary spring or too stiff of secondary spring(holds it in low gear, like driving your car in 1st all the time) or a combination of all of them. Your ideal set up will be all the rpm and track speed targets met with the lightest possible primary weight you can get away with. Thats the most efficient set up you can make.
M5
M5
You seem to have slippage in both clutches, can be due to a very slippery belt when it gets real hot,
I would definitively put in an spring with more sidepreassure, that doesent necessarily mean more torsion force as implyed above, an AC yellow is a really good choice, even an Yammi white works well @ ~60°.
Remember to scotchbrite the sheaves before a new belt.
I would definitively put in an spring with more sidepreassure, that doesent necessarily mean more torsion force as implyed above, an AC yellow is a really good choice, even an Yammi white works well @ ~60°.
Remember to scotchbrite the sheaves before a new belt.
Makes sense, I'm going to give Hartman Inc. a call and see if he has any ideas. I might just have to bite the bullet and try a whole different setup to get this thing to work. I'm sick of chasing this problem down! Any more input would be appreciated. I'll say I've learned a TON about clutching from these issues but it came with a heavy price tag...
I'm going to switch to an AC yellow secondary wound at 10* as per previous recommendations and this comment. As for the scotch brite....great little trick and I will definitely do it this time.
