oil questions

[kfx400rider03]

i just had my top end rebiult and just got it back yesterday. I was wondering wut kind of oil i should use. I bought AMS oil but that was about $9 a quart and i wanted to kno if i could use a cheaper oil that would still work as good.

and its a 2003 kfx400

[FASTDAD-77]

If you change your oil regularly, you don't have to use AMS oil or any other kind of synthetics. I have always been taught not to break a motor in on synthetic oil. I have had several motors sent off to have them built for racing and all of the engine builders I have delt with personally recommended something in the line of Bellray Thumper or something formulated for motorcycle engines. I use AMS oil in my son's TRX90 but I beak it in with conventional oil after every winter's rebuild.

[kfx400rider03]

k
thanks i'll get belray oil today and use that
and what could happen to my motor if i broke it in with synthetic?

[400exrider707]

Originally posted by kfx400rider03
k
thanks i'll get belray oil today and use that
and what could happen to my motor if i broke it in with synthetic?

The rings may never properly seat, and the motor will never be as strong as it could have been. Always break in on regular dino oil. Synthetics are great oils, but NOT for break-in!

[FASTDAD-77]

Since we're talking about synthetic oils, have any of ya'll ever heard that synthetics cause problems with auto-clutch ATV's? I was just wondering if there is any thruth to this.

[kfx400rider03]

i hav heard of that but im not sure if its true