SIDEWINDER UPPER GEAR FAILURE; AGAIN!

[ClutchMaster]

better yet run it at 1.5 turns out and see if your bushing lasts.

 

[ClutchMaster]

Of course the chain tightens under load. Explain why they all wear on a taper. I think that's the clue to solving this. In meantime I will just stick to replacement every season.

Have you ever tried 1.5 turns out?

 

[cannondale27]

better yet run it at 1.5 turns out and see if your bushing lasts.

What do you think I have been doing? It still does not last. You keep saying that so those that did and bushing still wears must now not be adjusting correctly right? This has been going on for 8 years now. You saying it's just adjustment is actually quite insulting.

 

[ClutchMaster]

What do you think I have been doing? It still does not last. You keep saying that so those that did and bushing still wears must now not be adjusting correctly right? This has been going on for 8 years now. You saying it's just adjustment is actually quite insulting.

Well actually no I’ve read we’re you have been recommending people run it at 3/4 of a turn out. I assumed that’s where you’ve always set it.

 

[ClutchMaster]

I have heard nothing but good bushing wear from running loose. People tighten it up more than the spec because it seems to be way loose. That’s where I went wrong. Couldn’t believe it was supposed to be sooo loose, so I set it like all my older sleds. Bad move on my part.

 

[cannondale27]

Well actually no I’ve read we’re you have been recommending people run it at 3/4 of a turn out. I assumed that’s where you’ve always set it.

Nope. Two seasons at 1.5 and wore both seasons. Same as at 1 turn out. Not running 2 out since chain hits boss even at 1.5. You did not read me recommending 3/4 turn out.

 

[cannondale27]

I have heard nothing but good bushing wear from running loose. People tighten it up more than the spec because it seems to be way loose. That’s where I went wrong. Couldn’t believe it was supposed to be sooo loose, so I set it like all my older sleds. Bad move on my part.

You just did from me and here https://ty4stroke.com/threads/upper-gear-bushing.149782/page-21 post 305. A quick read of the Viper posts will show majority had 1.5 out and still wear. 3000mi or one season it needs replacement for many of us. Not a big deal.

 

[ClutchMaster]

Sorry I missed that post. I think with the drilled holes and loose chain you might have better luck, but who knows? Mine was such a drastic reduction in wear with the loose setting I was sold. Who would have thought? No big deal just trying to cipher this out.

 

[cannondale27]

Sorry I missed that post. I think with the drilled holes and loose chain you might have better luck, but who knows? Mine was such a drastic reduction in wear with the loose setting I was sold. Who would have thought? No big deal just trying to cipher this out.

I know. I gave up years ago and just consider it on same level as oil change.

 

[ClutchMaster]

I know. I gave up years ago and just consider it on same level as oil change.

2000 miles @ 300hp and bushing looks great I’m fine.

 

[Turboflash]

Assuming one adjusts the chain as per factory spec, there will be a small amount of "play" somewhere. During acceleration since the jackshaft is accelerating in RPM, the chain will be very tight on the backside (between about 9 o'clock on the bottom gear and about 9 o'clock on the top gear). The "play" has to be somewhere but it's not on the backside during acceleration. So, either it's gone because the chain is spinning and it technically wants to form a circle, or the play is on the front side somewhere. Enter the spring loaded tensioner roller. I think its there to be able to move and absorb "play" when needed. During hard braking (and to a lesser extent during coasting or decelerating), the "play" moves to the back side and the front side gets really tight increasing load against the tensioner roller and spring. If the chain is too loose, IMO its more of a problem during hard braking than during acceleration because the sudden shift of the "play" from the front side to the back side which makes the tensioner slam against the adjusting bolt. At least during acceleration, even if the chain is too loose, the spring loaded tensioner can somewhat take up the slack enough to keep it from skipping or derailing. Too loose is not good. But, it seems too tight causes bushing failures. So, giving Yamaha the benefit of the doubt, they came up with 1-1/2 turns out from finger tight. It seems at that setting there's a better chance of acceptable bushing life. We need a scientific study under controlled conditions to definitively understand what in the world is going on in the that chain case (sometimes) to make it destroy that bushing. Some guys report long life with no virtually no wear, others with almost identical setups and sleds have very short life and failures. Frustrating, maddening, infuriating, etc, etc.

 

[ClutchMaster]

Assuming one adjusts the chain as per factory spec, there will be a small amount of "play" somewhere. During acceleration since the jackshaft is accelerating in RPM, the chain will be very tight on the backside (between about 9 o'clock on the bottom gear and about 9 o'clock on the top gear). The "play" has to be somewhere but it's not on the backside during acceleration. So, either it's gone because the chain is spinning and it technically wants to form a circle, or the play is on the front side somewhere. Enter the spring loaded tensioner roller. I think its there to be able to move and absorb "play" when needed. During hard braking (and to a lesser extent during coasting or decelerating), the "play" moves to the back side and the front side gets really tight increasing load against the tensioner roller and spring. If the chain is too loose, IMO its more of a problem during hard braking than during acceleration because the sudden shift of the "play" from the front side to the back side which makes the tensioner slam against the adjusting bolt. At least during acceleration, even if the chain is too loose, the spring loaded tensioner can somewhat take up the slack enough to keep it from skipping or derailing. Too loose is not good. But, it seems too tight causes bushing failures. So, giving Yamaha the benefit of the doubt, they came up with 1-1/2 turns out from finger tight. It seems at that setting there's a better chance of acceptable bushing life. We need a scientific study under controlled conditions to definitively understand what in the world is going on in the that chain case (sometimes) to make it destroy that bushing. Some guys report long life with no virtually no wear, others with almost identical setups and sleds have very short life and failures. Frustrating, maddening, infuriating, etc, etc.

One persons idea of a loose chain is different than another’s it’s a human error factor here.
When my chain is set too factory specs you can literally push it over and it’s only a 1/4” from hitting the center post, very loose IMO.

I will also say I replaced the chain with a new one and it’s very possible that a worn chain could have been contributing to the issue. With a new chain and loose setting it was unbelievable the reduction in wear, but it’s definitely chain climb causing this, not horsepower.

 

[stevewithOCD]

FIRST of all, the biggest issue is how much of a PITA it is to check & adjust the tension. Many don't all year.
I need to start bringing my sled home from Maine every other ride to check this and also crack cover & inspect in middle of season.

SECONDLY, I've heard 3 dealers' mechanics say they see a lot of milky oil due to moisture because these cases get hot according to them.
I may put a drain & filler plug in mine so i can refresh the oil more easily.

THIRDLY, i've heard that one Dealer said the fix is the bushing & Yamaha has a part # for it. Problem is i can't remember who told me or which Dealer he said so i'll make some calls this week. Obviously this bushing is a tad soft. There is no reason for it to be soft especially since it only rotates on shaft in reverse which is about .0000000000000002% of it's life.

FOUTHLY, this 1.5 turns out is sort of subjective. "Finger tight" can be a big difference hot or cold or Johnie Power Fingers.

MY SUMMER FIXES:
1. New bushing & hopefully a better one
2. Add a drain & filler plug
3. Shim top gear accordingly & check alignment to other gear
4. Weld adjuster roller
5. Maybe change chain

QUESTIONS:
1. Do we have an alternate bushing yet that we believe is harder & will last?
2. How many miles would a knowledgeable person change this chain with this much power?
3. Is there a better aftermarket chain & gears?

 

[74Nitro]

Chain tightens under load on both sides, not just the driven side.

Bushing wears more on the bearing side because the tension is so high it’s deflecting the 1” shaft downward so less load on the outside of the gear.

I think the bushing wears less on the right side because it is supported by the other gear that it is engaged into.

 

[ClutchMaster]

I think the bushing wears less on the right side because it is supported by the other gear that it is engaged into.

To be quite honest I couldn’t remember which side was worn more, it’s a non issue.
Theory’s have gotten totally crazy. I no longer have the problem and I’m positive with my solutions. Do what you will with what has been said. I’m getting tired of arguing so I’m done posting. Come to your own conclusions.
I’m unsubscribed