jeff350lc wrote:do you have to change it then
i use 5w30 or you can use motorcycle gearbox oil.
i,ve even run auto trans fluid in trials bike boxes.

I dont have to, no. But I dont know the history of the bike, or when it was last changed, or even when it was last ridden, so I'm going to replace all fluids etc..

So would 10W40 be the ideal to go for? Also, fully synth or semi?