engine oil

I have been using 10w 40 oil in my 400ex. i just wanted to know if i should keep using it or go to 20w 50. I race mx. thanks

i use 20w-50 hp honda oil, "in the gold bottle" and i race mx. i use 20w-50 in the summer and 10w-40 in the winter.

Dito

Ditto #2

Another question i bought the gold bottle HP4 and it has moly, do they make with out moly?, some one told me moly is not good, or were they just full of it? I hope so :-) this stuff is expensive

you are 100% correct ex 80, moly is bad for your 400ex do to it being a dry sump motor, the moly only hurts your engine if the oil is used for a extensive amount of time, like i said i change my oil after every race. it does cost alot to change so often but i want my engine to last long. its usaully every race but sometimes every other. if you want to use a oil without moly if you are using the oil for a longer period of time i would go with the honda gn4 20w-50 and 10w-40 that has no moly in it and works great.

exxxon

I may be wrong but is'nt GN4 only available in 10w 40 weight?

if your running an aftermarket cam and piston, run 20-50.