Boring the Kdx

boring the cylinder means to make the cyilinder bigger to fit a bigger piston, which means more cc's, and more horsepower. It probably will use more gas but I dont think it would be as much as your thinking. Porting means they clean up all the "ports"... exhaust and intake, then polish them for better airflow and such.

Note that if you bore, and don't get the ports modified to match by someone who knows what you are doing then it will not neccesarily run right. (probably won't) as the port timing is changed by the boring.

This is not like with a four stroke, where you can bore with no problems, two strokes use the holes in the cylinder walls for intake and exaust, so changing the cylinder walls, changes the port timing.
With a four stroke it is ok, as it uses valves that the two stroke does not have.

If you are going to bore, just send it somewhere with experience like Eric Gorr's Forward motion. Eric's shop will fix (and enhance) the ports at the same time - and more than just polishing them, he will change them for the better.

HTH,
Phil

keep in mind it is a plated cylinder...must then replate if you go for an overbore. If you go with a "big bore" package or kit to turn it into a 220, most likely that issue is addressed for you.

Glad you mentioned that - I didn't, thought it was obvious, but it is probably not to the guy asking.

A reputable shop like Forward Motion can do the replate too.

Phil