Yep, there are a lot of SPA designs that cry for a light 2-stroke. I'm gaining interest in the new OS AX .55 and might have to buy one soon. It weighs 14.25oz and is rated at 1.75hp/16,000rpm. That sound a lot like some those older, small-case sixties to me. The problem is it's b*** ugly:

http://www2.towerhobbies.com/cgi-bin...&I=LXNMD1&P=ML