2-stroke transmission/wet clutch oil

[Harley Anderson]

Back in my motocross days of racing 2 strokes we used supertech atf by gallon and changed the tranny fluid every ride. It would darken up pretty quick under hard use. Lots of other guys I knew was doing the same thing.

 

[Steve S]

Atf or straight 30.

 

[wileyE]

Oil never gets very hot in a two stroke gearbox so any oil that starts out thick pretty much stays that way. Thicker oil may (in theory) be better for the gears but is terrible for the clutch. If the clutch drags and makes shifting hard your more likely to bend a fork or damage the dogs. A thicker film between the plates can also take a few more revolutions of slip before it squeezes out and finds friction. This can lead to heat which can warp plate.

On a 4stroke the oil gets real darn hot and thin and it's not usually a problem , even with 20w50. On 4 stroke dirt bikes like the crf honda that separate the gear and engine oil in the same case there is more heat conduction into the gear oil side and a little bit thicker oil seems to work fine (for me anyway). 20w50 was too thick though.

 

[SmotalChaos]

what do you guys think of multi purpose tractor fluid for a 2 stroke wet clutch? theyre usually formulated for use with wet clutches and brakes, but maybe a little thick?

 

[ccdhowell]

I'm not familiar with this type of fluid. Could you pm me a link so I can look at what you're refering to?

Chris

 

[SmotalChaos]

http://www.cat.com/cda/components/secure...11&languageId=7


https://www.amsoil.com/storefront/ath.aspx

sry, i couldnt figure out how to post a true link.

the cat to-4 is what i am familiar with, the amsoil looks similar, but only meets cats to-2 specs, not to-4

 

[SmotalChaos]

nevermind, the links came up

 

[tmorris1]

Originally Posted By: Steve S
Atf or straight 30.


These 2 are very different viscosities.

 

[Steve S]

Originally Posted By: tmorris1
Originally Posted By: Steve S
Atf or straight 30.


These 2 are very different viscosities.
Transmissions as can use the 2.

 

[ccdhowell]

I changed my transmission oil again this evening on my race quad. It only had about 8 or 9 hours on it and it was that milky, greyish color when it came out. I refilled with the same Castrol MTX Synthetic that I've used almost exclusively on my racer with good results. I will tell you that I abused the clutch and trans gears like never before this past Monday. I had off and headed out to practice on my father's-in-law 40 acre plot. I marked off a short cross country course in the 15 acre pasture portion. It was more like a TT track, but was short cut grass and quite rough in places. I wanted to practice setting up for a corner and rotating the backend through a corner with the front brakes and as always I accelerate out of each corner very hard. i had never used the gears to help decelerate into corners, I don't like banging the gears down without the clutch and I don't like leaving the carb closed that long on a 2-stroke machine, I think it leans it out a bit.

Anyway, didn't miss many shifts and didn't grind any gears. I can imagine no tougher environment for an oil to exist and work in. Gears are ripping it to shreds and the wet clutch is pulling it apart, talk about shearing.

Sorry for the long post, I'm just excited about my race quad this week. I put a new topend on it a week and a half ago and a DynaPort headpipe and silencer, along with carbon fiber reeds. Turned my tired quadracer into a 450 killer. I have a race this weekend and i have a surprize for my buddies and their new 450s and 525s, they won't know what hit them.

Chris