Last season, I installed a new Nissan 9.8 on my 8,000-pound, 28-foot sailboat. I also installed the 5" pitch x 8.75" diameter, 4-blade HT Solas/Tohatsu prop. The tachometer showed that I was turning max RPM's in excess of 6,000, maybe up to 6,200 -- just below the rev limiter point. The correct...