This one was done before any parts were out there. I used a quadruple over sized Suzuki RM-60 piston and bored out the stock pyramid-reed cylinder over 1/4 inch! Super whole RPM range power and reliability! Great side-baskets for the market on Catalina. Update: I converted it with the new 12V PowerDynamo system together with a battery. I altered a Derbi DS-50 starter by reversing the motor rotation and flipping the Sprague clutch over and then shortening the housing for proper end clearances. Dead-centering the 3 holes into the PowerDynamo rotor was a real nail-biter, however.