My research shows that cylinder/pistons kits are interchangeable between the Bayou 220 and Bayou 250 models. The heads are the same exact part number but the cylinder, piston kit and gaskets are different. I am looking at rebuilding my 220 I just recently purchased with broken timing chain. Does anyone know if the sleeves in the cylinders are same too? I'm hoping to just bore out my 220 cylinder but if the 220 had a thinner sleeve, I may need to just buy a 250 jug. Thanks!

 

Can't really see the point. Any performance increase is going to be marginal. As you write, they may use the same size liner, it is only 2mm bigger bore and the max rebore for the 220, will be either 1mm or 1.5mm anyway. The outside of the liner, where it spigots into the crankcase mouth, may be smaller, and can get very thin if overbored. You will find out how much metal there is on that when you remove the cylinder.