Yamaha - after 27 year nap...with VIDEOS

[77SceptreOB]

The results were OUTSTANDING!!

The chart below summarizes the New performance:

RPM SPEED (MPH) GPH MPG
800 4 1.0 idle
3900 28.5
4000 29.1
4100 30.5 10.5 2.90
4300 32.3 11.5 2.81 (Optimal Cruise)
4600 35.2 13.3 2.65
5000 37.3 15.0 2.48
5400 40.8 18.4 2.22
5700 42.8 20.3 2.11
5800 43.3 21.2 2.04 (WOT)

The "Hole shot" was VERY strong with this 17" pitch prop.

I was totally impressed by this tuned up 27 year old 2 stroke Yamaha motor and had to share this.

Test conditions:

30 gallons of Fuel
Light load
One driver only
Aluminum prop in good condition ( 3 blade x 17" pitch)
Head Temp 140*
Engine water temp 130*