ORIGINAL: Nitroaddicted
Ok, from personal experience, what was a great high rpm .21 you've ever used. Just say the name, nothing else to prevent arguments.
on ebay they still sell NEW jammin JPX .21 for $230, thats what i run, rated for 3hp @ 30krpm and have a max RPM of 36Krpm, this is a very impressive engine, what makes it really shine is that the power is available at any rpm. i never had to touch the low speed needle, just a quarter turn of the high speed during the seasons.
one thing to note, this is such a punchy engine, it takes awhile to relearn how to feather the gas.