I have a '06 xpress X-17 with a yamaha 115 fourstroke on a 5 1/2" Jack plate. The propshaft is 5 1/2 " below pad. i cannot run over 5000 rpm without the motor reving up and losing speed. i have a 22" prop and my boat has a hydrofoil on it. I have read other people with my setup getting upper 40's and low 50's. I'm only getting low 40's. need help with setup!!!!!!