i have a 21' cuddy cabin with fiberglass hardtop, 1999 200 hp carbed johnson, 70 gal fuel tank 2/3 full, 2 batteries, (2) 200 lb guys on board, coolers, fishing gear and a 85 degree day. current prop is a 14.25 X 17. OEM book says operating range is between 5 and 6000 rpm. she will turn 5400...