bought a wee blaster the other day and i bought it with the bottom of the piston broke and of course when it did that it filled the bottom end so i split the bottom end and got all the bits out ,but i got a genuine yamaha ART piston today for it and it says on the top of the piston 50,not .50 or 0.50 it just says 50 ,it seems a wee bit tight when i put it into my head so im thinking i need it bored,can yous boys tell me is 50 over sized??it says on the box code:2XJ-11636-01 and in the inside of the piston the code is:37F01,so whats the story,pm me lads or what ever,thanks.......