Scott,

You may already know that the port timing can be increased up to .035” by removing or using a thinner base gasket. In the days of motorcycle racing it was not unusual to run with a single ring. It was also not unusual to shave the top of the piston in the exhaust port area to increase the opening time of the exhaust. Reversible changes seem like a better starting point for experimentation. I left the air box on my engine to prevent the loss of fuel charge. I have not experimented yet but did briefly turn one of my Ryobi’s 11,000 to verify that the magneto system was not RPM limited.

Good luck.

Bill