I've got an 86 250R that i'm restoring....and was thinking about porting it. What exactly is it, and how much power does it give you? I would mainly need mid range power. I know you port the intake and exhaust ports, but what else do you port? i've heard transfer ports? what are the transfer ports? any help would be appreciated

 

Someone out there has to know

 

Check out www.macdizzy.com that should explain every 2-stroke question you have...

 

In a nutshell, your cylinder has intake, exhaust, & transfer ports or openings. When a cylinder is ported those ports are ground out to allow the gases to be move in & out more efficiently and with more volume. Theres more to it than just making the ports bigger in size though. If done improperly it can ruin your cylinder. Here's a link to a place that sells templates that allow a person to do the porting themselves though if you're really interested in trying it yourself.

http://www.racelogic.com/

I don't know anyone that has used the templates so I can't tell you if they work or not. I myself didn't have the nerve to try it myself. I had Race Logic do my porting for me and I'm very happy with it. There's a definite power increase.