Clutch observation and issue. Calling clutch experts here.

[KnappAttack]

I digress. Any ideas why the belt returns to the top of the sheave with a weaker spring? It just does not make any sense to me.

Steeper helix returns the belt to the top easier as the sheave has to rotate less with less ramp travel.

The old sleds all ran steeper helixs with less length on the ramp, hence less travel on the helix ramp and less rotation of the sheave to get it there. Put a 60 degree helix in there and the belt will come right to the top quickly. Good luck getting that to work on the actual back shift and shiftout when under power on the trail though. High gearing will compound this effect as well.




This is not directed at ClutchMaster, but some of the squids who don't know any better:
Why is everyone so concerned it takes a few more revolutions to get the belt to the top anyway? WTF? Go ride em and quit worrying about something that's just not an issue in actuality. We don't ride them on the stand! When you come to a stop, don't lock up the brakes and there's no problem.

 

[ClutchMaster]

Deleted

 

[HMTurbo]

Steeper helix returns the belt to the top easier as the sheave has to rotate less with less ramp travel.

The old sleds all ran steeper helixs with less length on the ramp, hence less travel on the helix ramp and less rotation of the sheave to get it there. Put a 60 degree helix in there and the belt will come right to the top quickly. Good luck getting that to work on the actual back shift and shiftout when under power on the trail though. High gearing will compound this effect as well.




This is not directed at ClutchMaster, but some of the squids who don't know any better:
Why is everyone so concerned it takes a few more revolutions to get the belt to the top anyway? WTF? Go ride em and quit worrying about something that's just not an issue in actuality. We don't ride them on the stand! When you come to a stop, don't lock up the brakes and there's no problem.

Agree but with a Thunder 33/35 and stock spring in 3/3 mine won't fully return no matter how I stop on the trails or stand. Sled just keeps going.

 

[jonlafon1]

I digress. Any ideas why the belt returns to the top of the sheave with a weaker spring? It just does not make any sense to me.

I don't know but can assure you with a stiffer spring and the straight 38 it acts the opposite of what it should. This is with 8dn. Yellow green yellow yami primary spring. HH weights 58 gram base. 3.3 grams heel. .9 grams middle. 5.0 grams tip. TD eco trail and TD Turbo force muffler. The back shift and engine braking with the stiffer springs is noticeable more. Then compared to stock secondary spring. I can not get the secondary to open all the way on top end pull. Rpm is down and belt dust everywhere in secondary. Only change from last year was stiffer secondary spring.

 

[jonlafon1]

I digress. Any ideas why the belt returns to the top of the sheave with a weaker spring? It just does not make any sense to me.

I don't know but can assure you with a stiffer spring and the straight 38 it acts the opposite of what it should. This is with 8dn. Yellow green yellow yami primary spring. HH weights 58 gram base. 3.3 grams heel. .9 grams middle. 5.0 grams tip. TD eco trail and TD Turbo force muffler. The back shift and engine braking with the stiffer springs is noticeable more. Then compared to stock secondary spring. I can not get the secondary to open all the way on top end pull. Rpm is down and belt dust everywhere in secondary. Only change from last year was stiffer secondary spring.

 

[ClutchMaster]

Jon your running the cat yellow now correct? If so Is it returning better with the lighter spring?

 

[jonlafon1]

Good return with Cat yellow at 9/3. Very lightly twist. It's very close on rpm. Still going back to stock

 

[ClutchMaster]

Good return with Cat yellow at 9/3. Very lightly twist. It's very close on rpm. Still going back to stock

See what I’m talking about? Puzzling

 

[ClutchMaster]

View attachment 137079 View attachment 137078

More curvature more Force, especially at the end of the shift. 8fn vs 8bu a lot more weight actually less force at full shift. That’s the reason Stain can run a 45/41 helix with his clickers. Or you could run a straight angle helix and a primary spring with more rate to prevent overshifting.

Chaleurphantom,
I have answered a few of your questions and have noticed that others have also. I have yet to see you thank anybody for their free advice. Whether you agree or not it’s a common courtesy to thank people for sharing their opinions, after all you did ask and they spent time too reply.
Your welcome CM

 

[snowbeast]

OK now I have changed things around on allens advice,same blk/pink 30/90 primary but now 60ys stm tip weight only,1 tungsten and 4 washers for a total of 74.5 grms,secondary stm 42/36 on ulmer red/blk 4 coil wrapped 9-1 have not tested yet,this Thursday thru Monday I will.

 

[Big_Phil]

Just thought I would give an update here, since I started the thread. Thanks to everyone chiming in and giving advice, theres some great information in here.

My dealer changed the bushings in my secondary, and checked all alignments. Yamaha Factory rep said my belt deflection was set too tight as well. so now the belt sits just below the top of secondary. The belt still would not come to the top of the secondary with the stock spring, but it was much better than how it was in my video.

I took the secondary apart again, I polished the shaft the bushings slide on, and deburred the aluminum between the secondary sheaves. I installed the dalton black red secondary spring and wrapped it to 6-1, and now the secondary seems to close much better, and doesnt get stuck when jamming the brakes.

I now have 1200 kms on my current belt and it still looks great, all of those KMS I have been running the hurricane 270r flash. Ive done about 60 drag races with the belt, and I just did 500kms up in timmins, running hard and fast in cold temps.

My clutch setup is STM 60ys, dalton black teal primary with 5 glide washers, TPI secondary rollers and dalton black orange sec spring wrapped to 6-1. Clutches dont run overly hot and the sled is a monster corner to corner.

Theres still something wrong with the stock components in these clutches IMO. I know some people are saying dont stress about the secondary not closing properly, but this is not right, and is why many belts are being blown. The secondary rollers are still crap, and the Primary rollers seem to be not much better either.

 

[jonlafon1]

I just finished with another members sled. We changed a few things in the clutching. took a LITTLE tip weight off and went back to stock secondary spring. We installed a Barn of parts secondary adjuster(NICE part). We adjusted his deflection in secondary, and He is running stock belt(8jp). I do not run the stock belt in my sled.. I did notice its very hard to get the stock belt to ride high in the secondary. Nothing major, it sits JUST about even with sheaves. I run a 8dn belt(longer length) and it rides alot higher and have no issue getting it to come up nice. On a stand and doesn't mean much, but if your trying to get the stock belt up real high IMO it will not . Not saying the stock belt is to short(or bad) but it seems the 8dn comes up a bit higher and returns a bit better IMO. Just a observation and found it interesting. Also noticed his oil gasket is leaking slightly. obviously from the rollover valve creating pressure in oil tank. food for thought. By no means suggesting you should run a slightly longer belt(8dn).

 

[viper strike]

I haven't had any belt issues other that the above stated. ride height in secondary.
We rode 75 miles one way 76 back in 48f (scratches down obviously) No blown or frayed belts and we ride hard and long 75 miles without stopping.
Stock belts stock clutching.
Basically stock sled can only.

 

[krm]

I just got back from a trip in Maine testing my PT set up and the clutches are nice and cool.no blown belts ,and the sled revs 8900-9000 always .Using the OSP adjuster with no shim the clutch has some movement under load ,The Gates belt also works well As do the Dalton weights set up correct with the correct spring for how you ride ,with the stk.35 helix .One thing many need to learn to do is ,role to a stop ,don't slam on the breaks or it won't back shift correct .So far the thing rips and the btx seat is much better that the stk le seat .The sled also goes by my buds 850 like he pulled the shoot ,but the 850s are also a nice trail sled as are these spinegrinders .

 

[actionjack]

I just got back from a trip in Maine testing my PT set up and the clutches are nice and cool.no blown belts ,and the sled revs 8900-9000 always .Using the OSP adjuster with no shim the clutch has some movement under load ,The Gates belt also works well As do the Dalton weights set up correct with the correct spring for how you ride ,with the stk.35 helix .One thing many need to learn to do is ,role to a stop ,don't slam on the breaks or it won't back shift correct .So far the thing rips and the btx seat is much better that the stk le seat .The sled also goes by my buds 850 like he pulled the shoot ,but the 850s are also a nice trail sled as are these spinegrinders .

TD Power Trail?
Exhaust?
Whats your weight setup?
What track?
Thanks in advance