SIDEWINDER UPPER GEAR FAILURE; AGAIN!

[74Nitro]

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

Sure ya do. Post 29.
Anyway...c ya!

 

[ROCKERDAN]

My bushings look fine at 1.5 and also 3/4 turns.....no wear.

I did change oil several times due to other issues, and also checked tension often.

I am not convinced the turns out mean as much as alignment, type of oil, and level of oil.

And most importantly, how often oil is freshened and tension checked.

Since i was into mine a few times more then normal, I was changing oil more often and maybe that is why mine look great. Both a 22 and 21, both no holes at all.

Dan

 

[ROCKERDAN]

On a side note.....

I see the new 800 Cat 2s engine sleds have "engine reverse". RER like the doos and poos. Did Cat just get this technology? So now the 2s Cats will not have any mechanical reverse, which is why we all have this ridiculous chaincase design with this upper gear issue.

Dan

 

[NOS-PRO]

I will chime in as I just had mine apart to get switched over for racing asphalt. I run my tension very tight, more than the recommended and use Amsoil chaincase 100% synthetic.....no issues. This is on my winder that has been flashed at 265 horse at 10 miles on it. (10 miles was from clutch testing on grass)

 

[Turboflash]

I run same oil. 1.5 turns out. 3,000 miles and zero bushing wear. Wear on drive side of gear teeth as one would expect at 280 HP tune and lots of traction.

 

[Turboflash]

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?

Milky chain case oil is not from heat. It's condensation caused by repeated heating and cooling. Moisture vapor can enter the chaincase via the vent tube on the top of the case. Yes, the chain case gets hot courtesy of being attached to the engine oil tank that has oil returning from the engine at probably 180-200F. If it weren't for being attached to oil tank, I think the chain case would run allot cooler. In addition, the oil tank and chain case are directly "downwind" from the muffler and turbo so there's tons of heat. When the chain case and it's oil get hot, it actually causes any moisture to evaporate out of the oil which is good. (Ever seen oil from a car that gets short-tripped all the time? It's milky). So running the sled and getting it hot actually dries out the chain case oil and the engine oil but as it cools, some condensation occurs again. So, I too (like Rockerdan) service the chain case more than once per year for this reason as well as cleaning the magnets that hold tiny metal particles from things that are wearing, and checking to see if all is well inside. The whole condensation issue is one reason most sled manufacturers recommend not moving your sled back and forth from below freezing to above.

 

[ClutchMaster]

I will chime in as I just had mine apart to get switched over for racing asphalt. I run my tension very tight, more than the recommended and use Amsoil chaincase 100% synthetic.....no issues. This is on my winder that has been flashed at 265 horse at 10 miles on it. (10 miles was from clutch testing on grass)

https://ty4stroke.com/threads/chain-adjustment.125930/

https://ty4stroke.com/threads/frustrated-with-yamaha-chaincase-blown-at-400-miles.152137/page-3

Post 37

 

[northern srx]

Cat 2 stroke engine reverse has been around for more than 10 years.

 

[Crossfire12]

Any idea what size the washer should be?

Order from cat or Yamaha,look at diagram, it shows both, years back dealer changed my gears and didn’t put one in after awhile I stripped it going in reverse, WOBBLE popped out of gear.

 

[Crossfire12]

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.

Spring will keep tension

 

[ROCKERDAN]

Cat 2 stroke engine reverse has been around for more than 10 years.

Thanks I had no idea. Just was looking at specs on the 800RR and saw it.

 

[kinger]

I used to run royal purple 75/140W gear lube and it dramatically helped with wear in my apex chaincase vs the normal 75/90W. Got it down to a chain every other year and fluids once per year with the thicker oil staying on the chain longer. If the amsoil is helping maybe this is more lube related? Amsoil is 75W90, that is why I went to RP it was the only one that I found that got thicker. Maybe worth a shot.

 

[cannondale27]

I ran Amsoil in there one season maybe two. Still wore after about 3000mi.

 

[Doowithblue]

I used to run royal purple 75/140W gear lube and it dramatically helped with wear in my apex chaincase vs the normal 75/90W. Got it down to a chain every other year and fluids once per year with the thicker oil staying on the chain longer. If the amsoil is helping maybe this is more lube related? Amsoil is 75W90, that is why I went to RP it was the only one that I found that got thicker. Maybe worth a shot.

My amsoil is 75w/140.

 

[chaleurphantom]

View attachment 148142 View attachment 148142

Here are a few pics of my last gear with 1500 miles on it. Bushing is just about totally gone.

What isn't easily seen is that bushing actually spun inside gear. Oiling holes no longer align.

Service manager told me that last year they replaced 7 gears, this year 84!

Yamaha, we have a problem.