i know it may not have anything to do with these blaster engines, but we used to race kt100 go karts. there a yamaha single cylinder 100cc air cooled two stroke. we had 3 karts, and one had a stock engine from yamaha, one blueprinted by yellow fin racing, and one blueprinted by adkins racing. the stock yamaha engine we always geared it to hit right about 14,500 rpm's as you hit the brakes in the longest straight, and the two blueprinted engines about 15,200 to 15,500 and if i remember right they hit peak power about 12,500 to 13,000. i know these engines are built for this, but to me it shows that if a good engine builder tries, they should be able to get these engines to hit peak power around 10,000 with the right port mapping. and heat shouldnt be too much of an issue