I have to strongly disagree with removing the entire inner wall of the transfer ports, ESPECIALLY at the top of the wall, bottom of the port.

We tested a set of cyls done this way, in 1974, and it was a very large failure. In a jet ski or snowmobile, maybe OK, but not an H, S, F and even an A series Kawasaki engine, and not even in one of my TZ's as well.

The top of the transfer port, and the top of the cylinder at the bottom of the transfer ports are cut at the curvature they are, to enhance the mixture placement and angle for correct loop scavenging filling of mix into the cylinder/combustion chamber, and has NOTHING to do with overall flow rates others suggest are the "only" reason porting works, but to place the fuel/air mix in the right places on the top of the piston and up the rear of the cylinder wall. Remove/alter those curvatures in the transfers the WRONG way/method, and the mix doesn't get into the right place(s), tractablilty and power is lost.