440 ex big bore/oil

[deis]

what oil viscosity should i run in a 440ex big bore

[humblesquirel21]

i run castrol gps super bike oil full synethetic 10-40 it works great its expensive though 10$ a quart but it last longer than other oils cause its a full synthetic and it dosnt bother my clutch (i have been running it for 2 years now)
i hear ams oil is good to