First..This site is great You bikenuts on here are very helpfull I,ve owned many toys all my life,so I,m not new to atvs or bikes,BUT I dont know everything.. Here is what I wanted to clarify.I stopped in advance auto today to get some 4 stroke bike oil as per twomanytoys advise .Looking at the application it clearly states its a special formula for wet clutches.Now then I will soon have 4 atvs.I have 2 with semi automatics 1 totally automatic,and my yamaha warrior has a hand clutch.I usually run castrol 20-50 car oil in them. After reading about the wet clutch application it got me thinking? Should I be running that 4 stroke bike oil in just the automatic (and or ) the semi automatics.Should I be using it in the warrior too,or is it not nessessery?

 

Insane, bike oil is mostly a labeling thing. The only major difference might be that the bike oil has slightly higher amounts of some additives and lesser of others. I have run 20w50 car oil in several wet clutches for well over 100K miles with no issues whatsoever. In fact, it's always been 20w50 synthetic or synthetic blend, usually from mile #1.

But don't take my word for it, read these links:

http://www.nightrider.com/biketech/oiltest1.htm