I had a couple of Aprilla RS250's on the dyno a few days and ending up doing a simple compression test..

both read between 45-55psi depending how fast i kicked and how knackered i was feeling. The throttle was fully open when i was kicking too. Both bikes made about 57bhp and were stock so the motors must of been ok.

I guess a NSR engine should be something like the same compression but dont hold me too it.

Hope thats alittle help

Stephen