I have a '89 Yamaha XT350 Motorcycle that is 4 stroke and wondered if there is a real difference in synthetic 4 stroke oil vs the synthetic oil we use in our cars. On the bottles of 4 stroke motorcycle oil it states "superior wet clutch protection". Can I use standard synthetic motor oil in my motorcycle without issues?

Thanks and God Bless, Louis

Just stick with Yamalube and be done with it,

I had a 1996 XT350 up until a few years ago and it was bullet proof.

Excellent bike but now I have a 2006 WR450 and its a whole diferent animal all together



Cal30

I have never had a quad but I do have a a 94' Honda Goldwing and the only oil that I have found that is compatible with the clutch is Castrol (other than motorcycle grade oils). I only run conventional grade and cannot recommend their synthetic. I have known a couple of guys that have ran the 20W 50 Castrol GTX in their metric touring bikes up to a couple hundred thousand miles without damaging the clutch but I have only been using it for about 15,000 Mi.

I agree, car oils are too slipery for oil clutches. Bike oils have additives for those same clutches too...

DM

I suppose I should first put in the disclaimer about "checking with the manufacturer first" in regards to whether or not an oil is compatible with wet clutches, but "in general", most automotive oils that do NOT have the terms "high mileage" or "modified" will work.

However, that is not 100% accurate every time so here is something that is-

The US system that categorizes motor oils is called "API". In japan they have a similar system that is called "JASO". Jaso has two classifications for rating motorcycle oils. One is unmodified and the other has friction modifiers that unless your owners manual says it is OK you do not want to put in a regular wet clutch engine.

Anyway, to be sure an oil is wet-clutch compatible look to see if it has a "JASO MA" rating. If it does then it will be fine with a wet clutch system, whether it is synthetic or dino oil. "JASO MB" has modifiers and unless specified in an owners manual to be acceptable it may cause clutch slippage.

So just look up an oil you are wondering about, and if it is rated JASO MA you'll be perfectly fine.

some of the early models atvs did not requier a synthetic oil. stick with the owners manual. But DO NOT USE AUTOMOTIVE TYPE OIL. most of the time it is about the same price anyway..

Mark,
Spot On w/JASO wet clutch specs.

Castrol GTX 20W50 conventional engine oil in my 150+HP Japanese crotch rockets over the years is the only oil that did not FOAM.

Change it every thousand miles or so.
You are lubricating a wet clutch & transmission gears.

What about the opposite...synthetic 4 stroke motorcycle oil into cars/trucks?
...or mixing regular Amsoil synthetic with Amsoil 4 stroke synthetic?

Sorry to be a bit off topic, very interesting thread.