5w20 in a 2 stroke gearbox to reduce drag?

[Master ACiD]

im thinking of trying out fomr 5w20 or 0w20 in my 2 stroke gearbox to reduce drag. clutch slippage issues aside, what do yall think?

i know plenty of people who run atf in my same gearbox so i dont think the low viscosity of a 5w20 would be a problem.

opinions, please?

 

[wileyE]

Wouldn't be afraid to try it? My personal experience has been different bikes like different fluids so it never hurts to experiment. For example WAY back when, I had a maico and a ktm, the ktm loved dextron the maico hated it. Maico prefered 10w30, but was too thick for the ktm. A husqvana I had didn't mind anything you poured in there. If the 20w's had been around then I'd been given em a try.

 

[sunruh]

it will shear down quickly. change it every ride Master if you do run this oil.

 

[FowVay]

You could go out on a limb and use ATF. It's a approximate 7 cSt fluid but it has much better extreme pressure capabilities than does motor oil. After all,, it is designed to lubricate gears.

 

[sunruh]

Type F ATF is hardly out on a limb.
i used it soley for 2 years of racing in a '98yz250.
when i sold the bike in last 2000, the clutch pack was still in oem "new" spec.

 

[Master ACiD]

thats what i was thinking. i know alot of people who use type f for decades with no problems. sence a 5w20 is similar viscosity to a atf, maybe a motor oil has more ep adds and thats why i was thinking of using it.

 

[sunruh]

typo above, "late 2000" instead of last 2000.
that bikes transmission was so clean i'd eat off it any day of the week. it sparkled it was so clean.
i used pennzoil type f atf, changed it every race and it was always as clean coming out as it was goin in.

the big difference is that Type F ATF is designed for a gear box and 5w20 isn't. 5w20 is gonna shear down fast. mega fast. look what i've proven with the 10w40 tests. however, a uoa of either oil after being in the tranny of a 2smoker would be VERY interesting!!!

 

[KX 455]

I wouldn't do it!

 

[Cujet]

I have done it. It will work just fine. Even 0W 20 will work just fine. You may even pick up a bit more power thru less fluid drag.

Chris

 

[heynow]

I read a study about engiens with wet clutches that use shared engine/tranny oil. Said once the oil is bellow a 30wt the trans gears and other parts start to show signs of pitting.

 

[Jay]

Two-stroke motorcycle engines don't typically use shared engine/tranny oil.

 

[wileyE]

jay makes a good point, plus twostroke gearcase oil doesn't get all that hot compared with a 4 stroker. So ACID's 20w could probably mantain
as much viscosity as a shared engine/tranny 4stroker on 40w? Chris I did read the same advertisment, I mean study, so I know what your saying. Never seen hint of the problem with 2 cycles on ATF, so wouldn't think 5w20's would be a problem either.

 

[Master ACiD]

so what would be the concensus on which oil should i try, an xw20 or atf?

 

[FowVay]

Motor oil is designed to work in a environment rarely experienced in a gear box. Motor oils are designed for hydrodynamic environments where either plain bearing inserts or soft metal machined surfaces act as the bearing surface between high speed components.

Where a camshaft lobe rides against a lifter or a push-rod tube mates against a rocker or plunger the lubricant will utilize its boundary layer capabilities where anti-wear chemicals will perform the task of reducing friction on a molecular level.

Cylinder wall lubrication will be a combination of the two.

Two-cycle motorcycle gear boxes use roller/needle bearings to suspend the gear shafts and the clutch basket rides on a caged needle design and often uses a needle for actuation. These designs normally need a elasto-hydrodynamic fluid film to protect the bearing. The gears will need boundary layer lubrication to protect their mating surfaces along with the metal/metal contact experienced between the shift forks and the gear. The fiber friction plates of the wet clutch will also require a none-aggresive lubricant capable of carrying the extremely high surface temperatures away.

I would not use a SM rated ILSAC GF4 lubricant in a gearbox. I believe that all 5W-20 oils are designed to meet these standards.

I would use the lighter viscosity ATF due to it's EP capability and the elasto-hydrodynamic design characteristics. Detergents found in motor oil are unnecessary in the gear box and viscosity modifiers are also a non-issue.

I would not use a fluid such as the new DEX-6 fluid either because of the very low viscosity (4cSt).

 

[Harley Anderson]

I used to always use Supertech atf in my 2-stroke bikes, but the oil was changed everytime I rode. Supertech ATF is available at walmart for $4.?? a gallon. I never had a problem with cluctches except from my personal abuse racing motocross.

 

[Cujet]

What few oil experts ever do is what I do nearly every day. Ride a 2 stroke bike on the street.

I have plenty of miles and experience on 2 strokes, as it is the only kind of bike I like or own.

I have never seen any 2 stroke gearbox wear out using modern oils of any type or viscosity. There are so few failures that I would guess any modern oil will work. Yes, you may read of pitting on some 4 stroke trans gears. But I have never seen ANY oil related issues with the common 2 stroke gearbox. Even those who never change gearbox oil or run with contaminated oil have good results!

I did have an IT490 that lost a countershaft bearing. After a bunch of fishing line tore up the shaft seal and I did a 100 mile ride in the muck. That is what it takes to cause a failure.

I say 0-20, 5-20 or ATF is not a problem.

Chris