Synthetic motor oil?

Question

This is SmartBlonde's son.

I changed the oil on my 125cc 4-stroke dirtbike and used Sythetic otor oil, and now my clutch is rattling. Is it because of the synthetic oil or should I be looking for another problem?

Answer 1

yeah your gonna want to get that synthetic out of there. i know with most seals if you put synthetic in you never switch back to conventional because it will make your seals swell up and leak or give out.

Answer 2

Probably not related to the synthetic oil.

Answer 3

There is absolutely NOTHING wrong with using a good quality synthetic oil.  What you need to look out for is the syn. oils with the "friction modifier".  Look on the back of the bottle for "no friction modifiers" or "safe for use in motorcycle transmission applications".  Ive had an amazing experience with Amsoil synthetic motorcycle oil.  We bought a case and use it in all of our bikes, engine and transmission.

Answer 4

Not sure about dirtbikes, but i made the mistake of listening to my mechanic and he put syn in my sportbike, big mistake! Clutch slipped soo bad i had to replace clutch plates. that chit is slick! MAYBE A 50/50 mix would have been appropriate......just something to think about.

In comparision the syn is better than oil, but i would recomend mixing it. You have to change oil in dirtbike soo often that the extra cost and added lubrication of a syn isnt really cost efficient. just my opinion.

Answer 5

Synthetic oil is NOT slicker than dino oil .  I use it in three Honda motorcycles (Rotella full synthetic 5W40, the only  item I'll buy at Walmart). It actually performs better than dino oil in wet clutches.

The problem with using car oil is  the additives.  If the oil has enough "Moly" added it will cause your clutch to slip but this is usually with 10W30 and lighter oil.

(Some motorcycle specific oils have "moly" added, by the way.)

You may have cleaned deposits off the clutch parts that were dampening the sound.

I've switched back and forth, by the way,  The idea that you can't switch or that synthetic will eat your seals is incorrect and comes from the early days of synthetic oil when it was used exclusivly in jet aircraft.

Answer 6

I have heard not to use syn oil in a clutch. Too slippery. I won't use it at all. I beleive oil must be changed to keep it clean. Syn oil is made black so you can't see how dirty it is.

Answer 7

The synthetic oil is causing the clutch to slip because it is to slick. Change back to reg oil. Might be OK but you probably have ruined the clutch. Only way to fix is to replace the clutch..........UJN