That motor is a good motor. It's not as strong and torquey as the 2.5 liter motors, but it's a good motor none-the-less. There are a lot of simple things that can be done to the motor to give you some additional speed. Setup is key. A jack plate will most likely help you as will some prop testing. A boat like that will probably run well with a prop with moderate lift like a Lightning ET, a Cut Chopper, or a Yamaha Semi-Cleaver.
Tightening up the heads, opening the exhaust chest and raising the ports slightly will give you a reliable horsepower. We have had very good success with those mods and a tuner change in getting the motor to 240 hp without any loss of reliability.
Sam Baker
Baker Marine Support http://www.scaryfast.com