Prop Size / RPM Visited Again

[Melvin Hatcher]

I have a 2003 19'2" Key West Center Console fishing boat. <br /><br />Engine 1985 Evinrude XP 150.<br />Boat speed: 44.7 (GPS)<br />Engine RPM's: 4950 (W0T)<br />Prop OMC: 14 1/4 X 21+<br /><br />My goal is fifty + mph at 55 to 5800 rpm's.<br /><br />Help please!

 

[DH Zunic]

Re: Prop Size / RPM Visited Again

Da' Hammer, you'll need to increase in pitch. I'm running a 200GT with a prop size 13 1/2 X 25", my 21' charger runs 72 mph with it. You should be able to see 55 mph or just around that.

 

[jimmbo]

Re: Prop Size / RPM Visited Again

Make sure your engine is making all its power, if so, if you increase pitch and you'll go even slower. Try an 18" Raker. That will bring your rpms up to about 5500. The raker will raise your boat higher out of the water reducing drag and raising top speed. It will also allow you to trim higher and gives you the option of raising the engine higher on the transom

 

[Dhadley]

Re: Prop Size / RPM Visited Again

Ditto jimmbo.<br /><br />If you have a jackplate I might be tempted to try a 20" Raker or a Turbo. Both have lots of lift. Getting the rpm's up is the key.<br /><br />Also, keep in mind that while your XP (crossflow) and DzBimmer's GT (looper) are close in horsepower, his GT has gobs more torque.

 

[LubeDude]

Re: Prop Size / RPM Visited Again

Originally posted by DzBimmer:<br /> Da' Hammer, you'll need to increase in pitch. I'm running a 200GT with a prop size 13 1/2 X 25", my 21' charger runs 72 mph with it. You should be able to see 55 mph or just around that.

Where did you come up with that one, he is allready under his recommended RPM, with a higher pitch he would never even get up on plane.

 

[Melvin Hatcher]

Re: Prop Size / RPM Visited Again

Thanks guys,<br /><br />Saturday, I am going to try a rebuilt 14, something or other X 17 that a friend of mine will loan me for a trial. <br /><br />This will I think allow me to decide which way to go in pitch. <br /><br />It will be good to hear the old XP scream up in mid to upper rpm's again.