I think we might see a TRP 4-stroke somewhere in the future. I had the opportunity to talk with Phil Dyskow, the Yamaha CEO, in Vegas back in November. He said they would take a look at making The F150 has the same bolt pattern as the DX150TRP. I shouldn't be too much work to make it happen. That being said, they simply don't have the demand needed to spend R&D dollars on TRP technology. Yamaha only sold 200 TRP's in 2005 which was the last production year. The motor was developed to be the fastest 150 class motor on the Bass Master circuit. After Bass Masters removed the 150 hp limit the motor became virtually obsolete. It was only by accident that someone figured out it's the best shallow water motor ever built.