Looking to get my prop right on my rig. G3 1448 with aluminum deck. 2015 yamaha 15hp 4 stroke tiller. Im estimating my weight at 600 to 700lbs. Stock prop 9.25 x 10p 3-blade was only getting me to like 4800 rpm's. Bought a solas amita 4 blade 7p and now im only able to go 3/4 throttle before...