Originally Posted by mapbike
Scott you took the words right out of my head, I don't know much about doing a reed set up on these engines either and don't know what the overall benefit is other than maybe better low end response or something, which by the way I could be wrong about......?
Reed ports are supposed to match or rise above the stock transfers by 1mm. That huge transfer port, because it doesnt rise above the piston, is perfectly fine (dont worry about rounding the edges, the rings never come into contact with the port).
The reed port is also supposed to be approximately 5mm wide and at a shallow angle aiming toward the top of the cylinder so as to not blow the side transfers straight out, but rather drag the flow up, and through the middle toward the exhaust to improve scavenging. The boost port is smaller so it has more pressure, so exhaust gases wont want to melt your reeds. A good idea is to stuff the crank case after reed porting to keep your pressures up, with the extra port, the transfer pressures drop.
However I would have opted for the piston window rather than that huge transfer, simply because of the weight reduction reducing vibrations, and allowing gas/oil to blow by and lubricate and cool your wrist bushing/bearing.
Still looks beautiful like that, I wish I had the money to do stuff like that.