hi bill, i have the m25 bearings and a rod kit for this motor,( cheeseslice`s ol bike?) as far as i know the pistons are avail original 71mm or 72 mm, sizes inbetween are avil @ around 300eurouch, i can bring the bearings over or will have em @ rnd 5
250 gs (aircooled right?) 83mx was watercooled
got a repair manual & spare parts manual for this model also
give us a ring if you want the bearings & rod kit b4 rnd 5 871 6588 waikato
cheers Daz #38