These little GN's are pretty gutless, try & find a 1984 -87 Suzuki NZ 250, these are a DOHC 4 valve bike that produce 34HP @ around 12-14000 RPM. A very nimble little bike using the engine as a stressed member, hence an open frame, fitted with a progressive link mono shock rear end & disc front & drum rear brakes. I'm going to build a cafe racer from two engines & frame & forks I have acquired.