Check the backside of your sidewinder clutch

[yamamarc]

The set screws control engagement. The more they are screwed into the weights, the lower the engagement will be. unscrewing them towards the belt and the engagement goes up.

If the sled is running, the weights are centrifugally forced into the rollers all the time. The only time they will not be in contact with the roller is when the sled is shut off. They don't "bounce" on the rollers when running. Centrifugal force will keep them in contact at all times with the roller...

I played with it last season. With the weights untucked and in contact with the rollers it definitely has less rattle. Engagement the way I have it is at 3000

 

[KnappAttack]

I played with it last season. With the weights untucked and in contact with the rollers it definitely has less rattle. Engagement the way I have it is at 3000

It would because you are also applying spring pressure at that point, in other words you are leveraging against the spring at that point preventing the rollers and weights from moving side to side with the harmonics and pulses of the engine crankshaft. Which is where the rattles come from is the side to side movement in the clutch. So in essence you have added weight to the rollers by also pushing against the spring, so makes total sense that's it has improved the rattle.

None the less, what I'm trying to say is the pressure of the weight is always against the roller if the engine is running. Most people do not have set screws in the movable face. You don't see engagement set screws normally on a trail clutch. Its more common on an old race clutch for engagement purposes by tucking and untucking the weights on the heels. Drag racers have been doing this for 30+ years, but not used so much anymore, I'm surprised your clutch has this for trail use. Be sure to keep those things loctited or bad things can happen...

 

[1nc 2000]

We ran the set screws on our f111 sled back in the late 80's. Worked great for holeshot.

 

[SledFreak]

To add to my original question... The key on the crank shaft, will it fall out when I pull the stub shaft? Is there any way to tell the position of the key so I can have it sitting on the top, so it is easier to re-install the shaft? Also, have you ever seen where the shaft has moved on the bearing or is it mostly the bearing moving on the housing? Also, did you remove the stub shaft from the bearing or just the bearing from the housing and leave the shaft and bearing assembled. If the bearing gets destroyed while trying to remove, what is the part number for a new one.. Thanks..

 

[Fords4life]

To add to my original question... The key on the crank shaft, will it fall out when I pull the stub shaft? Is there any way to tell the position of the key so I can have it sitting on the top, so it is easier to re-install the shaft? Also, have you ever seen where the shaft has moved on the bearing or is it mostly the bearing moving on the housing? Also, did you remove the stub shaft from the bearing or just the bearing from the housing and leave the shaft and bearing assembled. If the bearing gets destroyed while trying to remove, what is the part number for a new one.. Thanks..

No key to fall out, only indexing of crank and stub you cant mess it up, can leave bearing on stub if good and has not moved on stub, you will see if it has moved away from end of stub, pretty hard to wreck bearing if you use a bearing seperator with the press, press stub shaft out of bearing tetaining housing with bearing on it, put back together with green locktite, #280,243, 224 i believe are some of the locktite #s i used #280 in the housing and stub to bearing( new bearing for me) posted bearing number earlier in post for a less clearance type.

 

[Fords4life]

No key to fall out, only indexing of crank and stub you cant mess it up, can leave bearing on stub if good and has not moved on stub, you will see if it has moved away from end of stub, pretty hard to wreck bearing if you use a bearing seperator with the press, press stub shaft out of bearing tetaining housing with bearing on it, put back together with green locktite, #280,243, 224 i believe are some of the locktite #s i used #280 in the housing and stub to bearing( new bearing for me) posted bearing number earlier in post for a less clearance type.

Here is stk # and tighter clearnce #

 

[Fords4life]

No key to fall out, only indexing of crank and stub you cant mess it up, can leave bearing on stub if good and has not moved on stub, you will see if it has moved away from end of stub, pretty hard to wreck bearing if you use a bearing seperator with the press, press stub shaft out of bearing tetaining housing with bearing on it, put back together with green locktite, #280,243, 224 i believe are some of the locktite #s i used #280 in the housing and stub to bearing( new bearing for me) posted bearing number earlier in post for a less clearance type.

Correction my bad, locktite # 680, sorry about wrong #s

 

[NYTurbo]

Here is stk # and tighter clearnce #

Tighter clearance where ?

 

[Fords4life]

Tighter clearance where ?

Is it not?? Im not a bearing expert, had stock one in hand when i went searching for a replacement, was talking with parts man at bearing supply house and i said i wanted a tighter less slop bearing, the skf in picture is what he handed me two of, installed them both..no more side to side "slop" and less clutch chatter. If im wrong im sorry not trying to miss lead anybody, just trying to help out a fellow snowmobiler, merry christmas to all.

 

[Sevey]

Just to share my experience:
When I was changing this bearing on my 2010 nytro I had a hard time finding it from a bearing supplier.

When I did and gave them the rpm spec and likely heat threshold it exceeded that particular bearing.

If not 100% I would stick with the koyo bearing from yamaha.
Ms

 

[NYTurbo]

Is it not?? Im not a bearing expert, had stock one in hand when i went searching for a replacement, was talking with parts man at bearing supply house and i said i wanted a tighter less slop bearing, the skf in picture is what he handed me two of, installed them both..no more side to side "slop" and less clutch chatter. If im wrong im sorry not trying to miss lead anybody, just trying to help out a fellow snowmobiler, merry christmas to all.

If you had side to side slop that bearing was pooched. I think both stock and the skf one are both C3 bearings . I'm no bearing expert either but if there is indeed a better bearing readily available I'm all for it

 

[Turboflash]

"C3" means looser than standard internal clearance inside bearing. Don't confuse that with bearing ID or OD. The ID and OD and width are always same for all 6307 size bearings. C3 internal clearances are typically used for applications where the bearing is subjected to high heat, high RPM, or a bearing that is fit to shaft or housing with high amount of press fit. High heat causes reduction in internal clearance in bearing due to expansion of raceways and balls. High interference press fit uses up internal clearance essentially by expanding the ID and/or compressing the OD putting these two closer together.
A bearing with no "C3" indication has standard internal clearance which would be less than a bearing marked "C3". One needs to be careful about using a standard bearing in place of a C3 bearing because if the conditions are such that all the internal clearance of the bearing gets used up (press fit, heat) then the bearing will have what's called radial preload and it will fail pdq.
I don't think we can find out what Yamaha's design specs were for this bearing but my guess would be careful and purposeful engineering thought went into deciding to use a C3 bearing. My guess would be that they wouldn't have used C3 if a standard bearing would work under all conditions. However, I think guys have used a standard 6307 and it seemed to work. Again, the design decision to use C3 comes from calculations and not necessarily lots of testing.

 

[Kent Smail]

I too had a suspect stub shaft bearing and was not able to find a replacement. So I email KOYO and this was the reply I got... So with those specs a guy might be able to find one that works... Any of the 6307 bearings I found locally were not rated for more than 6000 rpm.