Seems like 4100 rpm and 20.6 mph with the 9x6 prop is my final number, with my BackH20 26.5 EFI, for which I am most pleased. After having removed and replaced the cavitation plate several times in the process of dialing in the motor and trying out a different prop, the rubber gap seal at the top of the plate, which "seals" the gap between the plate and shaft housing is stretched, mostly from my mis-positioning it. Anybody replace this yet? Seems like I could use a piece of rubber hose and cut a slit in it and slide it over the plate edge. Any suggestions for size/brand/material for this?
I will probably do a few more runs, with both the 9x6 and 9x7, this time simulating a hunting load, and then decide which prop to use.
By the way, while the boat was in the water, I installed some EZ slide pads on the trailer bunks. Amazing how much more easily the boat loads/unloads from the trailer now! Why didn't I do this years ago??
I picked up nominally .5 mph. I tweaked the throttle up to 4300 rpm but I have hit a plateau at 4100 rpms @ 20.5 mph. This is with the 9x6. I will test again with the 9x7 and more weight up front and then determine what may be best.
$3.64 for 6', should last a while 5