Any Four Winns 201 Liberator guys out there?

[tntitans21399]

I have my dad's old boat, 1986 Four Winns 201 Liberator (5.7 V8 engine with cobra drive). My question is gps has the boat topping out at 42 (44 on real smooth water). Every where I look, everyone else is getting 50mph and the manual says top speed 50-52. It has a 19" pitch prop which is what the manufacturer suggest. I have changed the lower unit gear oil. I haven't had time to change the oil (has enough oil in it) and change the fuel filter (it starts up fine and sounds like it is running fine). The ram guage doesn't work so I'm not sure what rpms it is running at, but sounds to be running normal. Are are some things I should be looking at to get to the 50mph mark?

 

[DeepCMark58A]

Compression test of the engine how many hours on it, what are the rpms at top speed?

 

[jbcurt00]

Weighed it lately?

 

[southkogs]

Trim might come into play as well. But I'm thinking the same thing JB is ^^^