Big bore kits

[frdbronco8]

I have my 06 yz250f for about 8 years. When I bought it I was told it had a big bore kit and the stock cylinder was included in the box of parts. I was cleaning the bike and noticed that the cylinder says 249cc and looks just like the stock cylinder...  

Is there a kit that looks stock to be sneaky and is there a way to tell? Getting ready to sell it and want to be honest with any buyers.

[mikedabike]

They may have bored the stock cylinder. You would have to measure bore and stroke to find what displacement it is.

[Vintage Not Pimpage]

I rebuild a YZ250F the other day that had a cylinder works 80mm cylinder on that looked completely stock from the outside and had 249cc on it like a stocker.  

 

[Vintage Not Pimpage]

I took a photo...

Was on an ex A graders bike.. dodgy 

[sndmn2]

My Athena 290 on a 02 250f is just the cylinder and piston. 

[frdbronco8]

Thanks, this is what I was hoping. I knew some of them looked close to stock but the 249cc on the side surprised me.

[CDNSXV]

I had to go look but my 270 cylinder says "249" on the side.  ?