1989 cr250 porting?

[az_762_nato]

Lemme start off by saying that Im not new to bike, engines, 2 strokes, engine work, porting, etc. I have an 89 cr250 with stock carb and an fmf fatty pipe and shorty silencer, v force reeds, and 2 degrees of ignition advance. Ive never ported a cr250 before so Im looking for some decent specs to port it to. Im looking for midrange and top end, but top end mostly. Bike is getting torn down next week for a top end. Im just new to the honda single cylinder 2 strokes so any advice on where to start for port specs would be appreciated. I have not yet degreed the bike stock to see where its at. Thanks in advance,

Jeff

[az_762_nato]

anyone????

[drag lt guy]

mid to top end you'll need an agressive port layout. I'd say something like a dune port would work good for what your needing. I know that port durations arent all there is to porting but I would try something like a 195 exhaust 128 transfer. But for some more tips talk to our site sponsor FloTek