I'm going to try and make this as short as possible. I thought I'd try porting a 372 Farmertec cylinder before I try it on an OEM cylinder, so I got my pencil grinder out and widen the exhaust and intake 1mm. I matched the cylinder to a crankcase and knife edged the lower transfer dividers. I looked a little ruff which was ok because this was just to get the feel for grinding. So, I rebuilt a 372 this week and decided to put this ported cylinder and a pop up piston on the saw to see how it would run. It didn't run bad but I couldn't get the rpm above 12900. I tried two 385 carbs and a 372 Walboro with the same result. I didn't put a degree wheel on it so I don't have any numbers. The question is, what controls how high a saw will rev? Any help would be appreciated.