Sidewinder upper gear with oiling hole?

[fatchance]

Even inspected the washer up against the cir-clip behind the top gear and there was zero sign of pressure there.

 

[ClutchMaster]

My same experience on 280 & now 320 tune. 21T top gear bushing looks like new after about 2000 miles this winter on 320 tune. However, gear teeth faces look like there is severe pressure against them by the chain (and there is @ 320 ). Gonna need a new gear and chain every year. Bushing looks like new.

I’m speaking of this gear tooth pic, the wear is on the non drive side

 

[fatchance]

.

 

[74Nitro]

I’m speaking of this gear tooth pic, the wear is on the non drive side

No, that is the drive side.

 

[74Nitro]

These little sprockets suck especially with big power.
These type of chains don't like being wrapped around small diameters. Problem is that there is a lack of lower sprocket choices when running larger top sprockets to get the desired ratio.

 

[ClutchMaster]

My same experience on 280 & now 320 tune. 21T top gear bushing looks like new after about 2000 miles this winter on 320 tune. However, gear teeth faces look like there is severe pressure against them by the chain (and there is @ 320 ). Gonna need a new gear and chain every year. Bushing looks like new.

My bad it’s on the drive side, I was thinking backwards

 

[ClutchMaster]

I will say it seems like you have done everything correctly. Gear fretting is a sign of lubrication film breakdown. If you want to actually reduce chain torque switch to larger gears top and bottom. A larger gear on the top will reduce chain torque but increase its physical speed. Going to larger gears top and bottom will reduce stress on the components.

 

[KnappAttack]

It almost appears from the pic of the bad teeth on the gear that perhaps the chain is just too loose and barely making contact in the sprocket, either that or the oil just isn't good enough.

I've never had a gear look like that before.

 

[Turboflash]

These little sprockets suck especially with big power.
These type of chains don't like being wrapped around small diameters. Problem is that there is a lack of lower sprocket choices when running larger top sprockets to get the desired ratio.

Yeah that is a 21 gear. So much pressure on it from 320 tune and lots of long studs the chain plates just dig into the gear teeth. Chain has a scissor action as it goes around gear. Running 38 bottom. 21/38 = 1.81
Scott Taylor has 25/45 = 1.80. I'd like to try this to see if there is less wear on 25 tooth top gear cuz it's bigger. Anyone know if there is a long enough chain for 25/45?

 

[Turboflash]

It almost appears from the pic of the bad teeth on the gear that perhaps the chain is just too loose and barely making contact in the sprocket, either that or the oil just isn't good enough.

I've never had a gear look like that before.

Umm, well IDK . Been running 1.5 turns out, Amsoil Synthetic. This gear has 2500 miles on a combination of 280 & 320 tune.

 

[Turboflash]

BTW - this was a 13-wide gear I took out and replaced with a 15-wide one with oil holes. I'll be taking a look at it soon.

 

[KnappAttack]

BTW - this was a 13-wide gear I took out and replaced with a 15-wide one with oil holes. I'll be taking a look at it soon.

Are you sure that 13 wide is a HYVO gear and not a silent chain gear? When did they use a 13 wide up top?

 

[ClutchMaster]

Well it sure looks like a hyvo gear, they have a round tooth at the crest. The vipers had 13 wide gears.

 

[KnappAttack]

Well it sure looks like a hyvo gear, they have a round tooth at the crest. The vipers had 13 wide gears.

It does look like a HYVO, but I had to ask.

Power does not eat gears up like that, something is not meshing properly from its appearance in that pic, or the lube is completely lacking.

 

[Turboflash]

Are you sure that 13 wide is a HYVO gear and not a silent chain gear? When did they use a 13 wide up top?

Going by description it should be BW = hyvo: 1702-410 (OEM Arctic Cat Part SPROCKET,BW-21T REV-(13 WIDE/33 SPLINE)).
Now running 1702-490 (OEM Arctic Cat Part SPROCKET,BW-21T REV-(15W/33SPLN)OIL HOLE)