After posting this in the Forum, I decided to email Klotz and Mobil1.

Here is what I wrote:
Can I switch from conventional 4 stroke oil
to Synthetic oil in my 2001 Yamaha Warrior ATV?? Will it make it leak or
anything?

KLOTZ REPLY:
You can switch to a Synthetic, go back to a petroleum or mix them with no
problems.

MOBIL1 REPLY:
Yes that will be fine.

Guess I'm going to try it!

 

dude, i seriously wouldnt chance it. I think we all know most car oil and gas addiditves are BS that do more harm that good, but do u think if u emialed the company and asked if it would hurt your engine they would say yeah? of course not. instead of running synthetic, just take car of your quad and change the oil every 15-20 hours. good luck

 

Synthetics can cause leaks heres why if your engine has a bunch of hours on it it will have a deposit at the edge of the seals . when you add synthetics they remove the old build up and the tolerences are to large == they start to leak .
If your engine is fairly new No problem . How ever they may not be suited for a wet clutch .
AS for oil additives Dont waste your money . Most use a additive call Clorinated Parrafin . It turns to acid nuff said I have a good friend that used to sell ER until he was milling a head using ER after he was done his Mill table was etched . Kinda scary

 

If you use synthetic, go with Valvoline's 10/40 atv 4 stroke oil. I've used it through two oil changes with no problems at all. The bottle will actually say ATV 4 stroke 10/40 in big letters on the front, and it was designed for wet clutch systems specifically, you can't miss it. If it's not available in your area you should use the half and half mixed ones such as the Yamaha oils, and so on from the dealer. That Valvoline stuff gives me ultra smooth shifting and great performance though. NEVER use the bullsh*t for a car, I'm sure it's a bad idea!!!

 

I have used synthetic oil in 4 of my quads, and all of my vehicles for over 6 years. They don't leak, smoke or any other of this other nonsense. My wet clutches have never slipped, either. I will not use anything else.

There are a lot of wives tales out there.

 

it shouldnt hurt it of affect it at all, there is things tho called friction something in some car oil, use oil with none of that int here

 

So no one here has switched to a synthetic after their ATV was a few years old? Darn boys, Im as confused as a baby at a topless bar! One minute ready to try it next minute im not. My motor shows no sign of wear or leakage, Just want to do the best for my motor.

 

All of my quads were used when I switched to synthetic. Never owned a new one.

At present, I am using Mobil 1 MXT4 motorcycle specific synthetic.

 

Seems to me I'd be thirsty if I was a baby at a topless bar.. just an observation.

On the oil topic, it's an interesting question, and everybody seems to have different ideas. A synthetic without friction modifiers should be fine if you use it either from new, or after the engine is broken in. With an older engine, it may cause leaks for a lot of the reasons already mentioned. I've been thinking of changing to synthetic myself, considering how hard the engine gets worked. However, I think I'll stay with either the GN4 or another decent quality 10w40 conventional oil, and keep the oil changes as regular as possible. I checked mine a few days ago, it was changed in November and I've probably put maybe 20 hours on it since then, and it's still remarkably clean, and the level hasn't dropped at all.