Is this the motor you have? It says 5000 to 6000 RPM at WOT (page 47 of document.
http://www.yamaha-motor.com/assets/s...07-16_1395.pdf
Or one of these two? Either way the WOT range is still 5000 to 6000 rpm. What is your current WOT rpm?
http://yamahaoutboards.com/sites/def...26-09-96_2.pdf
http://yamahaoutboards.com/sites/def...26-09-96_1.pdf