2005 Keywest 1720CC Propeller

[cpkeys05]

I just bought a 2005 1720 with a 90hp Yamaha. The guy I bought it from was the original owner and because of his age and health, the boat has next to no use. It's in almost brand new shape, garage kept.
That said, he had put a Solas SS prop on the boat and its a 13.25 x 17.

When testing the boat I didn't think much of it but now I am doing some research and thinking more about it. The boat was running about 29MPH on the GPS and turning 4500RPMs @ WOT. I was able to trim it out a little and get up to about 4650 but it would start to porpois.
I pulled the Test bulliten for the 1720Pro, same motor and hull shape, the test bulliten showed WOT @ 5500RPM @ 38MPH.

Could it be the prop??? The bulliten shows that they the Yamaha Stainless painted black prop that is a 13 X 17. Could the rake or cup on the Solas prop be creating this poblem.
Or could there be something with the motor? It runs great, fires right up idles smooth, no hesitation on take off (jumps out of the hole), runs smooth at full throttle. The motor runs like a champ so I was wondering if there is something with that prop that is causing this.

Wondering if anyone else with the 1720 has had this or what their experiences are???

Thanks

 

[wildspeed]

Re: 2005 Keywest 1720CC Propeller

Use to have an Evinrude 90HP on a similar size boat and was also running a 17 pitch, was getting 36mph at 5400rpm.

If the prop is in good shape, I will think something wrong with the engine or the throttle cable adjustment

 

[cpkeys05]

Re: 2005 Keywest 1720CC Propeller

It was my fault. I had only tested the boat before buying it. Yesturday we took it out for a ride afterwork and it performed as it should. The more I trimmed it out, the more the RPMs increased and the GPS unit had been set on Knots so the reading was lower. Once I changed the units of measure to MPH, I was able to get to 39MPH at 5200 RPMs.

Thanks for the reply.