Numbers On Piston, Standard Size Or Other?

[rm_racer]

Hey,
Well, it was time to do the top end (did a comp test and it was down to 90 from 130 2 months ago). Well anyway, I have the piston out and the cylinder off and stuff. Theres some numbers on the piston and I dont know what they mean. I think its a wiseco piston, or thats what the guy who sold it to me told me. It doesnt say STD or anything.

What is on it is
BOOD1

641M05400

CS
(down arrow)

The bike is a 94 RM125. I think it said in my manual the cylinder is coated.

Im going to bring it into the dealer when I order a new one anyway, but I just thought I would ask here first. Also, am I going to need the cylinder honed?

Thanks!

 

[marcusgunby]

yes that sounds like a wiseco number the m05400 says its 54mm(std) as for honing you will get hundreds of opinions on this but i never hone.