Wrong piston size in bore

[2strokerdie]

Quick question for you guys out there. Is it even possible for a blaster engine to start with a standard piston and a .020 bore. Someone I know is claiming that it ran like that. Even if it did I'd think it would make a hell of a racket. Just curious if anybody has ever experienced this

 

[jus_me]

It could/would run sure.

 

[speedyslyder]

if it had enough compression to explode the piston down n up
then yes till the piston broke/taking out a list of other parts

 

[blasterkid1998]

Bought an 87 yz125 a while back and it had a brand new stock bore wiseco in a sleeved cylinder bored .020. I didn't know it till i pulled the top end and measured. The bike idled fine and ran alright. hard to start. Had about 75 lbs compression.

 

[2strokerdie]

Thanks for the replies guys. Didn't think the guy was bs'in me cause he's not that kinda guy but I just wanted to double check. It just seems like it would b awfully noisy though. I guess with it being a 2 stroke and if u really didn't know what to listen for how would u know. I'm helping him fix it, cause it wasn't starting from lack of compression, and I miced the bore and saw the numbers on top of the wiseco piston it was pretty obvious what the problem was. I just couldn't believe it ran cause the bore didn't get all beat up nor did the piston. Guess he just got lucky. If that was mine I'd be splitting the cases cuz the piston would have broken in a million pieces. That's just my luck.