Clutch observation and issue. Calling clutch experts here.

[Big_Phil]

Phil.....As I said, sure this can blow a belt under certain circumstances riding on/off throttle hard.

But just trying to say, that many blow belts for other reasons, as mine did.

No wrong or right here, just all of us trying to work on these.

Ya, I wasnt trying to say im right and your wrong or anything, just that many sleds seem to have this problem with snapping belts. My sidewinder and my brothers, the secondary clutches both dont snap closed. Does every sidewinder do this? I have heard of many having the exact same issue. One tuner told me to try a stiffer secondary spring as well, and I will once theres more snow. If every sled does this, theres needs to be a fix or a recall from Yamaha, if its just my sled, then Yamaha should step up and fix my problem under warranty.

This is just frustrating because I bought this sled to have less of a headache than my Nytro. So far its been the same crap, ive spend way too much time tinkering with it, driving back and forth to the dealer, etc etc.

Now Im out $400 worth of belts, have a sled with a broken side panel, and some clown from Yamaha telling me I cant drive my 19 grand high performance snowmobile fast and hard.

 

[ROCKERDAN]

Ya, I wasnt trying to say im right and your wrong or anything, just that many sleds seem to have this problem with snapping belts. My sidewinder and my brothers, the secondary clutches both dont snap closed. Does every sidewinder do this? I have heard of many having the exact same issue. One tuner told me to try a stiffer secondary spring as well, and I will once theres more snow. If every sled does this, theres needs to be a fix or a recall from Yamaha, if its just my sled, then Yamaha should step up and fix my problem under warranty.

This is just frustrating because I bought this sled to have less of a headache than my Nytro. So far its been the same crap, ive spend way too much time tinkering with it, driving back and forth to the dealer, etc etc.

Now Im out $400 worth of belts, have a sled with a broken side panel, and some clown from Yamaha telling me I cant drive my 19 grand high performance snowmobile fast and hard.

Mine does same thing with massive backpressure. So its not the issue for me.

I have never rode mine On/OFF throttle hard for the most part.

If you told me you snapped a belt in half, when OFF/then ON throttle very hard right away, id totally agree with you and say that is why it snapped....

For me it snapped on accel....a slow roll accel too.....It was 270r map that "drove right thru" my belt til it let go. IMO it was too much backpressure in SEC and the HP just pulled right thru it before SEC could even open. And it was the ultimax that everyone seemed to have best luck with, so that theory is out the window. But I dont think any belt could hold up to the clutch combo.

Dan

 

[Big_Phil]

Mine does same thing with massive backpressure. So its not the issue for me.

I have never rode mine On/OFF throttle hard for the most part.

If you told me you snapped a belt in half, when OFF/then ON throttle very hard right away, id totally agree with you and say that is why it snapped....

For me it snapped on accel....a slow roll accel too.....It was 270r map that "drove right thru" my belt til it let go. IMO it was too much backpressure in SEC and the HP just pulled right thru it before SEC could even open. And it was the ultimax that everyone seemed to have best luck with, so that theory is out the window. But I dont think any belt could hold up to the clutch combo.

Dan

Have you fixed your issue? Me and my buddies have never had good luck with any aftermarket belts, even on stock apex and nytros. Always run OEM or some run the gates carbon when racing. I see you are running a reverse angle helix, and the thunder orange secondary spring. Those seem to be unnecessary with the 270r tune, and likely causing alot of heat in your secondary.

Thats exactly how my belts snap. Hard on the brake, belt stick in secondary, hard on gas, boom. My clutches run warm when doing multiple drag races, and when running hard trail riding, clutches are lukewarm. I have been avoiding the hard on brake, hard on gas situation, and I got 800 kms on my current belt and it looks great, but I should have to ride brand new high performace sled like this.

https://ty4stroke.com/threads/clutch-offset-stms-and-stock.150838/

I know these are stm clutches, but look at how secondary closes nicely. Thats how a clutch should work IMO.

 

[snowbeast]

You just need a stiffer secondary spring is all.
That soft 8jp belt doesn’t help matters either.
I doubt twisting the existing spring will help much.
I would switch to the 8dn belt and stiffer spring.
if you insist on running the 8jp belt run a slightly higher helix angle like a 38 degree, and stiffer spring.

Clutchmaster is correct,my sled was all over the place with stock 35,when I got my tune and clutch kit from ulmer last year,it was set up with stm 38 on red/blk secondary spring at 10 degrees,with stm weights at 80 grms on a pink/blk primary spring at 30/90 rate,and run great but low rpm,so we swapped out the 35 to help,ya brought rpm back but did not backshift or up shift like the 38,now I have it back in,and it hauls the mail,and no belt issues.

 

[snowbeast]

If you want to be a Pioneer get a 42 degree helix and run the arctic cat red/white secondary spring. Guaranteed it will come to the top of the sheave even if you hammer the brakes! Secondary will only need 3~4 revolutions for it to return with that spring/helix combo! I bet it would accelerate like a beast too. M2C

Funny,that is my next helix to try,but with a finish angle of 36 and I have that cat spring to.

 

[Big_Phil]

Clutchmaster is correct,my sled was all over the place with stock 35,when I got my tune and clutch kit from ulmer last year,it was set up with stm 38 on red/blk secondary spring at 10 degrees,with stm weights at 80 grms on a pink/blk primary spring at 30/90 rate,and run great but low rpm,so we swapped out the 35 to help,ya brought rpm back but did not backshift or up shift like the 38,now I have it back in,and it hauls the mail,and no belt issues.

What do you mean all over the place? Youre running an evo tune then?

My clutching works perfectly for trail riding and drag racing, just I think there is something wrong with the design of this secondary, or there is somthing wrong with alot of the secondary clutches where they dont close properly.

My sled has been doing this even with no studs, stock power level and stock clutching.

 

[snowbeast]

What do you mean all over the place? Youre running an evo tune then?

My clutching works perfectly for trail riding and drag racing, just I think there is something wrong with the design of this secondary, or there is somthing wrong with alot of the secondary clutches where they dont close properly.

My sled has been doing this even with no studs, stock power level and stock clutching.

Yes EVO tune stage 4 but my rpms were crazy with the stock 35 changed to what allen had sent me,38 straight,and now it hooks and books,and so far no belt issues at al. I really like the pull of the steeper helix,next one is 42.

 

[Big_Phil]

Yes EVO tune stage 4 but my rpms were crazy with the stock 35 changed to what allen had sent me,38 straight,and now it hooks and books,and so far no belt issues at al. I really like the pull of the steeper helix,next one is 42.

Ya thats completely unrelated to whats going on with mine here.

My clutch setup works great actually with the stock helix. On antilag launches, gets out of the hole nice and hard at 8300 rpms then quickly gets up to 87-8800 and stays there. No rev limiter bouncing, not much heat in the clutches. Those evo tunes dont have the boost come on as hard as the hurricane race tunes, so secondary setup would be a little different I believe.

 

[jetpilot785]

Where do you have the degree settings on the black/orange spring set at?

 

[Big_Phil]

Where do you have the degree settings on the black/orange spring set at?

6-1. It was at 3-3 before, makes no difference in the secondary being able to fully shift closed or not. The 6-1 is a little snappier for trail riding, I like it better.

 

[STAIN]

That does not seem right at all. Have you taken your secondary apart and run it through its cycle without the spring?

 

[jetpilot785]

6-1. It was at 3-3 before, makes no difference in the secondary being able to fully shift closed or not. The 6-1 is a little snappier for trail riding, I like it better.

The Tangs on the Dalton spring compared to the location of the stock spring are completely different and the 3-3 setting that it uses on the stock spring is not even close when trying the same 3-3 setting on the Dalton spring. The tangs on the Dalton spring are almost in line with each other and have no where near the torsional load it should. Needs to be in 6-1 or 6-2 to work properly. I noticed in the video it was in the 3 position on the helix so I'm guessing its 3-3 which is incorrect. I also noticed you were hitting the brakes when revving it on the stand. You need to let it come down on its own. Another thing to test is after it comes to a rest is slowly spool up the secondary but don't allow it to shift and see if the belt walks its way to the top. The 8JP belt will not go all the way to the top but it comes alot closer than I am seeing in the video. Also check shimming and see if the deflection is wrong keeping the belt too low. Looks to be alot of slack in the primary to take up and that is part of the reason belts are blowing. Too much shock drawing in all that slack. I would also take that clutch apart and clean the faces and check to make sure you don't have any debris or bushing binding going on. Check rollers for flat spots and if you follow this, there should be no reason why the clutch should not shift properly.

 

[Big_Phil]

The Tangs on the Dalton spring compared to the location of the stock spring are completely different and the 3-3 setting that it uses on the stock spring is not even close when trying the same 3-3 setting on the Dalton spring. The tangs on the Dalton spring are almost in line with each other and have no where near the torsional load it should. Needs to be in 6-1 or 6-2 to work properly. I noticed in the video it was in the 3 position on the helix so I'm guessing its 3-3 which is incorrect. I also noticed you were hitting the brakes when revving it on the stand. You need to let it come down on its own. Another thing to test is after it comes to a rest is slowly spool up the secondary but don't allow it to shift and see if the belt walks its way to the top. The 8JP belt will not go all the way to the top but it comes alot closer than I am seeing in the video. Also check shimming and see if the deflection is wrong keeping the belt too low. Looks to be alot of slack in the primary to take up and that is part of the reason belts are blowing. Too much shock drawing in all that slack. I would also take that clutch apart and clean the faces and check to make sure you don't have any debris or bushing binding going on. Check rollers for flat spots and if you follow this, there should be no reason why the clutch should not shift properly.

It was at 3-3 In the video. Makes no difference at 6-1. This sled has the same issue with all the stock clutch components in it. 10* of wrap won't make that much of a difference.

Deflection is perfect, on the tight side If anything.

Watch the second video of my nytro clutches. Look how they perform the same test. Belt always snaps right to the top of the secondary even when I stab the brakes. I just jammed the brakes to illustrate how bad it is. It's very easy to lock up the track on the trail, and even letting the sled roll it doesn't come to the top.

It is leaving lots of slack in the primary, that's exactly why it's snapping belts. I haven't snapped a belt in 800kms because I know how to avoid this happening on the trail, but this is not how I should have to ride my sled.

Clutches are spotless. The sheaves are clean. Only rubber marks are on the outsides of the clutch from blowing them. I left those marks for the dealer to see. Rollers are aftermarket. New bushings were installed in the secondary. I think I need a new secondary clutch to be honest.

 

[ClutchMaster]

Clutchmaster is correct,my sled was all over the place with stock 35,when I got my tune and clutch kit from ulmer last year,it was set up with stm 38 on red/blk secondary spring at 10 degrees,with stm weights at 80 grms on a pink/blk primary spring at 30/90 rate,and run great but low rpm,so we swapped out the 35 to help,ya brought rpm back but did not backshift or up shift like the 38,now I have it back in,and it hauls the mail,and no belt issues.

Yep yep when you switch to the 42 helix try about a 40~50* wrap on that red/black cat spring right? That should really haul the mail! Won’t ballon the belt anymore either.

 

[jonlafon1]

If you want to be a Pioneer get a 42 degree helix and run the arctic cat red/white secondary spring. Guaranteed it will come to the top of the sheave even if you hammer the brakes! Secondary will only need 3~4 revolutions for it to return with that spring/helix combo! I bet it would accelerate like a beast too. M2C

I'm betting it back shifts and engine breaks like a beast also. Just a guess though.