2 stroke bottom end oil

[Mr.Jake]

I currently use 10w40 in my ytm 175, but was wondering, since its basically the tranny, would it be better to use a thicker oil, such as 75w90 gear oil, or a transsmision oil (auto or manual?). My only worry is the clutch, any thoughts?:beer

[NINJA]

Gear oil is the way to go. For racing an auto clutch though, Atf is better for shifting and soaks less horsepower. Since you have a YTM and won't be racing, hypoid is the oil.

[Mr.Jake]

so thicker is better, i should use this 75w90 instead of the recommended kind. I thought it made more sence.

[NINJA]

You're going to open a canOworms on this one, trust me. No, I hate the thicker oil, the shifting sucks with it, but yes, your tranny will last longer.

[pickleweasel_00]

I dunno, since the tranny in a sense works like an automatic tranny (with the clutches and all) I figure the reccomended weight is what you should use. Then again, unlike an automatic, it isn't trying to force the oil through valves and small passages either

[NINJA]

Here we go.....

[pickleweasel_00]

either way, the reccomended weight will be a good starting point if you are going to play around with different oils

[Tri-ZNate]

alot of the 250r guys use 80/85W honda tranny oil. Would seem like Yamaha would have a Yamalube for the trannys if you went to a shop. Also ATF I hear works as well.

[Mr.Jake]

before i start experimenting i need to know one thing, tranny oil or gear oil wont blow my trenny to hell will it?

[Tatersaladx]

No its for your transmission, and go with spectro clutch saver

[300rman]

ok. put into the bottom end what the MANUAL says to use.....the 84R is supposed to have 10w40 oil in the tranny.......

if a manual is not availible, call the dealer, they will be able to tell you.

noone knows better what is good for that tranny than the manufacturer......they built it.

[ccdhowell]

I know this has been covered and beat to death many times, but I wanted to straighten out one thing on this go round that I haven't mentioned before for fear of wrinkleing someones undies; 10w40 motor oil and 75w90 gear oil are basically the same thickness, see Bel-Ray viscosity chart below. The Society of Automotive Engineers, which set the viscosity scale, thought it would be less confusing to use different weight scales for oil intended for different purposes. The fluid viscosities of 10w40 motor oil and 75W90 gear oil are very similar with large overlap between the two. The transmission on a 2-stroke bike is a unique lubrication environment, wet clutch which shears the hell out of lubricants at the molecular level as well as contaminates the fluid and a gear set which must be protected with special anti-wear additives and anti-shock loading additives. This combination can only be achieved to optimum levels in the specialty 2-stroke transmission fluids sold by the various oil makers, i.e. Bel-Ray's Gear Saver, and Maxima's MTL. In these fluids the 75 weight corresponds to 10w30 motor oil, the 80w corresponds to 10w40 motor oil and the 85 w corresponds roughly to 20w50 motor oil. So whatever the old manual calls for in your bike, choose the correct specialty transmission oil and you can't go wrong. I do agree with Ninja with respect to a lighter fluid loosing less horsepower. Also, many people find that the 80w or 85w fluids shift better. On my Tecate, a 85w specialty fluid from Silkolene is the best for shifting. I am currently running Bel-Ray Gear Saver, 75w.

Chris