I looked at various websites to see if a 1998 klx300 cylinder would fit on my 2006 klx250s. They all show they are different part numbers due to the 300 vs 250cc's. I have a chance to buy one from a friend but I just want to be 100% before hand. Is it a direct swap? Thanks, Fred.

 

Check on the web that the base gaskets are the same, some of the 300 barrels (early ones) are a different outside diameter were they fit in to the crankcase.

 

Just did a quick check and the cylinder base gaskets are the same part numbers. So it looks like its a good match. Thanks for the help, Fred.

 

The problem with 300 cylinders not fitting some 250's was based on the older...back in the 90's...crankcase opening on the older 250's being a touch too small to fit the 300 cylinder extensions into the crankcase.