Please give advise

[quad]

I just recently purchased a used 400ex from a dealer.I want to change the oil.Problem is,i dont know what kind is in it.If its synthetic,and i put petroleum in it,will it harm the engine?If its petro.,and i put synthetic in it,will it make the clutch slip,engine smoke?Ive been told to use amsoil,castrol (somthing),gn4.Please give me your opinions as to what would be the best and SAFEST type to use.Im sure ill get flamed hard for this.But thanks in advance for any help.

[300exOH]

Mobile 1 red cap is about the best. Make sure it is wet clutch approved(no friction modifiers). Try a search there are many threads on this subject. You can use synthetic or conventional oil as long as it's safe for a wet clutch. Good luck and enjoy that 400

[hook]

honda oil.10w40 cold mounths. 20-50 in the summer

[brandonpeake]

dont use the honda oil or any brand like that yamalube etc, they take bids and whoever will sell them the oil for the cheapest is which oil is used so its usually a 3-5 yr deal sometimes only a 1 year deal but it changes all the time same goes for the quicksilver oil thats 2 stroke for outboard motors, it kills me when people swear by the oil and dont even know which kind of oil it is

i run golden spectro 20w50

[hook]

hell yel thanks for that info. learn new things everyday:D

[quad]

If the oil in it now is petro,will it smoke if i use synthetic?Because of higher detergents?What if it has synthetic in it now,and i use petroleum,will it hurt the engine internals?

[brandonpeake]

im not positive ive heard if u go synthetic u need to stay with it but im not sure, if its petroleum it will be darker and thicker than syn oil, what model is it? does it have any mods done to it? ask the honda shop u bought it from they are supposed to service all quads they sell. im guessing its got honda oil in it!

[miken]

You can switch anytime. It's just that when your breaking in your motor you want to be using petroleum oil so the rings will seat. After the break in use whatever you want as long as its rated correctly for your clutch. Some engines like the CRF use 2 separate types of oil, one for clutch another for top end.
Mike -

[wilkin250r]

Do NOT use a synthetic automotive oil. I cannot stress this enough. If you use synthetic oil, make sure it is a dedicated motorcycle oil. Yes, I know it is more expensive.

Most synthetic automotive oils have friction modifiers added to them. These friction modifiers can cause problems with a wet clutch.

Synthetic motorcycle oils do not have friction modifiers.

[quad]

Thanks for all the input guys.What is a real good petroleum oil to use other than honda,if i dont want to go the synthetic route?

[woprs50]

i like to run castrol or mobil petroleum and i like mobil 1 for synthetic im gonna start running the black cap mobil one in my bikes it just sucks that its 8 bucks a quart

[416mx]

I use Valvoline ATV 10-40, get it at Autozone, about 3 bucks a quart.
I just put it in my brand new 426 motor and really like it. :D

[nastynotchback1]

i use bel-ray 10w40 and it seems to work fine.cost like 4.50 a quart.

[hondarider2006]

I run Mobile 1 red cap 15w-50, and I think a majority of the people on this site also run it and would recommend it;)

[brandonpeake]

i run golden spectro atv oil i have run it in several modified motors and have had no problems for it and one of my sponsors gets it to my by the case so thats cool also