Clutch Slipping???

[Nytroman]

Lately I have noticed a possible slip or non engagement of my clutch. Basically when I first start out riding it seems like my primary is not grabbing the belt. It seems to happen about 30 seconds to a minute after I start riding. It revs up but the sled goes nowhere and after giving it a few seconds of rest it starts working again. I can't understand why this would be because it is after I have already driven a few hundred meters that this happens. I noticed that it happened a couple times last year, but I wrote it off to the very cold conditions that we were riding in. This year however it happened to me many times throughout the day. I have no odd wear marks on my belt so I am inclined to think that the primary is sticking open. I have the D&F clutch kit installed, but it seems to work perfectly when I am not experiencing this problem. The clutch looks fine to me other than maybe being a bit dirty. Has anyone had this same type of issue or have any idea what I can do to fix it? I am in a real bind as I need my sled this weekend for a very remote location ride. Any help would be much appreciated.

 

[06attaker]

Mine seems to do this around 30MPH. If I lightly press the gas at 30 the motor will rev up but no more acceleration...

 

[billymx815]

What's model & year is the sled? Have you set the belt deflection? If so what brand of belt are you using? How long have the D&F been in?

 

[Nytroman]

It is the standard 08 Nytro. I have not set the belt deflection, not sure how to do that. The belt seems to be riding at the proper height on the secondary. I installed the D&F half way through last season. Also I put it in my heated shop for a couple days to thaw out and when I pulled it out last night it did not slip. I am thinking this is only a coincidence as the last ride I went on there was no ice build up because I had thawed it out a few days before.

 

[billymx815]

It is the standard 08 Nytro. I have not set the belt deflection, not sure how to do that. The belt seems to be riding at the proper height on the secondary. I installed the D&F half way through last season. Also I put it in my heated shop for a couple days to thaw out and when I pulled it out last night it did not slip. I am thinking this is only a coincidence as the last ride I went on there was no ice build up because I had thawed it out a few days before.

If you go to the FAQ section of this site there is a thread from Ulmer Racing on setting belt deflection. It can have a big effect on clutch perfromance. I will also tell you from my experience the Yami belt is great for wear & tear but not so good for performance. Many Nytro guys are running aftermarket belts...big advantage.
Last but not least take a close look at the primary spring and make sure it's seated properly. I heated a clutch up on a Viper once and the primary spring did something funky (can't explain) but replaced it and problem solved.

 

[Nytroman]

I will try to take a better look at the primary spring, I took a quick look at it yesterday and it wasn't broken so I figured that wasn't the issue. I hope this is not the problem as I do not have another Red spring to through in it and there is no way I can get another by Thursday. It is a Yamaha belt. It is relatively, new I have maybe 300 to 400 km on it having changed the last one with around 2200 km on it and it was not worn out. Maybe I will give an aftermarket belt a try, any brand that is better than the other?

 

[billymx815]

You'll open a can of worms with suggestions for belts...Carlisle, Gates, Kimpex, SLP, Dayco, etc...I've used Carlisle with good results but others may chime in here.

 

[Nytroman]

I beleive that I can get a Gates, Carlisle, or Dayco on short order so I supposed I could start there. Thanks for the suggestions thus far.

 

[**sj**]

belt dust can build up in the towers and impede the slider pucks..(binding) and the cover bushing...remove and clean with fine steel wool...use compressed air to blow out...

assuming all is set correctly and the belt is within tolerance the other possibilites would be if the belt isnt returning in the driven due to helix / button and or helix bushing binding..

or a possibly water is getting into your clutch area (wet left foot related) very wet clutch slipping the belt

 

[Nytroman]

Well there is definately alot of snow in there i.e the very wet left boot, as we were riding in very powedery conditions. I never thought of the secondary sticking though. I will check the helix and see how it looks. I was trying to avoid taking apart the primary because that red spring is a massive pain to get on without a second set of hands. I guess I may have to just bite the bullet and take it apart and give it a good cleaning. Hopefully I can wrestle up another set of hands to help put it back together.

 

[MOUNTY]

I think sj hit the nail on the head, if the secondary is binding the belt will not return to top of sheaves causing the exact problem you are finding, like taking off in second gear. Definately check your buttons as they seem to wear out first. The yammy buttons are pretty expensive and no better than aftermarket which are a fraction of the price.

Did you score your cover bushing after intalling the RED DEAMON in the primary clutch? If scored or gauged enough it will bind on the shaft.

 

[Nytroman]

I don't think that I scored the bushing, but I do recall a lot of choice words while compressing it so I suppose with all of the pushing I could have. Sounds like I should be taking both clutches off and having a good look at them. I have about 2500 km on the sled so I guess the buttons could be worn down by now. Man I am glad this site exists; some of the simple things can slip a guys mind. Thanks a lot guys.

 

[**sj**]

from what you are stating now...Im leaning toward the snow/water slip...if you get snow in this area...its at engagement your slip will occur and be most noticeable due to the minimal contact patch (belt area touching the sheaves)...

 

[Nytroman]

I have no doubt that the water and snow were not helping the slipping situation. The problem is that it also slipped at the beginning of our ride before I had enough time to get any amount of snow under the hood. I suppose it is possible that I have not been getting it dry enough before sticking it back outside, but it also was not slipping until the end of last year. I am thinking that I should be closing off some vents anyway; being that cold weather is never an issue here.

 

[**sj**]

I worked on a members sled last year where he had so much belt pitch in the towers the movable sheeve would bind up...