Cylinder porting adds 3 hp to 23-26 KTM 300 TBI bike. No loss, only gain in mid to top and over rev
At pinit racing we've finally figured out the correct porting changes on the 300 TBI cylinders. This SX cylinder gained a lot of power, just fixing the casting problems.
Thing is, if you don't know what you are doing and have the right tools to cut the nikasil plating, you will quickly ruin your engine.
So trust the one that knows. Also a gain on the 125/150 and 250
https://www.pinitracing.com