xr 250 valve stem replacement Help

[CHEWEYCHEWT]

ive just fitted new valve guides into the head of my xr 250r 1998. When i went to fit the valves the stems were to thick for the new guides. Did honda change the diameter of the valves in the motors at some point? or do i have special valves!!!!!!

Can anyone help,

[416cc]

I replaced the guides on my Honda XL250SA and the guides had to be reamed out to the correct size.The valve seats also needed to be recut on the 45 degree angle.