250EX, noise when shifting

[dads400ex]

My sons 2002 250EX is making a rather loud ratcheting or almost a grinding? noise when he shifts between all of the gears. I thought maybe it was the way he was shifting but it did it when I rode it also. I know the noise is not right, but I was wondering if anybody else has had something like this happen with them and what it was or may be, any ideas?

Thanks,
dads400ex

[brokeitin3]

A dealer once told me that golden spectro engine oil would cure this problem but ill wait till its time to change it first.:rolleyes: