Freeair and Finchase4,

Thank you both for your suggestions. I was considering a YS63 but may look into the Magnum. Don't know much about the Magnum line of 4 strokes. I really wanted the OS 70 FS II but was dissapointed to see it discontinued. I want the engine to have the power and torque to hoover and other aerobatics. Do you think the OS 55ax will have the vertical torque I will need? Doesn't 4 strokes have my power and torque that 2 strokes? What are your comments