F9.9FMH Power output

Jorn · 27 July 2012, 11:53

My dad bought himself a new outboard to replace his old two-stroke 9.9, but it seems a bit of a "wet fart" compared to the old engine. Is this something to expect from a four-stroke or is there an easy way to increase the power output? When increasing the the throttle there is no difference in output during the last 20% of the travel on the handle. Any suggestions apart from replacing it with a bigger engine?

willk · 27 July 2012, 12:45

Is the top speed down or is it just a lack of acceleration?

Jorn · 27 July 2012, 22:12

Top speed is down I think. Considering the possibility that the prop pitch is too big, preventing it from reaching max RPM. Have not had the option to check what max RPM is yet. Did a test run with the old 9.9 Evinrude 2 stroke engine today and got 12.5 knots vs 10 knots with the new Yamaha F9.9 FMH.