It's actually a pretty straightforward principle. Mounting twin propellers on a single shaft and having them counter-rotate balances thrust to offset steering torque. It virtually eliminates chine walk and provides twice the bite when you hit the throttle. 150 TRP the world's first production outboard with twin rotating propellers has put a whole new spin on outboard performance. You experience no cavitation or ventilation, and excellent ability to hook-up and accelerate in shallow water.
Cruising speeds are more efficient because fewer rpms are needed to stay on plane.
Bow lift is diminished and the skeg profile is higher and wider, improving overall boat handling at all speeds. For 1999, you have the option of adding Ox66 Electronic Fuel Injection. Of course, mere words can't begin to convey the difference TRP makes. So visit your Yamaha dealer for a test drive. Try TRP once, and you won't have to think twice.