RPM at WOT

[MASTER Brian]

Re: RPM at WOT

Would you want to raise a motor that was installed at a certain height from the dealer new?

Considering my boat is 20 years old, who knows if it's been messed with, but I'm curious. It's apparantly all factory and I may not even have a problem. I just want to learn just in case...

 

[Dhadley]

Re: RPM at WOT

By maxing out the existing set up we mean making sure the motor is running as good as it can (compression, cooling, fuel delivery, ignition etc) and the adjusting the motor height (X dimension) for max efficiency for the prop you already have. We're always amazed at how inefficient rigs are that come from dealers or even from factorys.

A 90 hp motor on a Glastron 162 should easily turn a 17" prop more than 5400. We're not really sure what boat Jason has but if it's the one in his pic, his 200 should spin the heck out of a 17.

Now, not all props are created equally, nor do they all age gracefully. Some lose their bite rather quickly. A 19" Ballistic isn't the same as a 19" Stiletto or Turbo. And there are different styles within brands that are different. A 19 3 blade Stiletto isn't the same as a 19 4 blade Stiletto. Or a 19 Offshore Turbo. Props are getting so specific that there are actually desiginated models of props for specific models of boats.

Try playing with X dimension. We also play with setback, which changes the balance point or lift point. Try moving things around in the boat, like batteries. Or gas tanks if they're portable. You might be amazed at what you find you already have.

 

[Jason Edwards]

Re: RPM at WOT

The boat in my pic is of my boat. Its a 23' Center Console Promaster and is built like a tank. On the trailer with full fuel it weighs 4600 pounds (and thats with no gear or people).

The new prop came in yesterday (14.25 x 17P Rapture). I ordered the high volume screens as Dhadley suggested and they should be in by the weekend. I am gonna try to make it to the lake Sunday morning. I'll let you know how it goes. With the high volume screens I hope to be able to jack the motor out of the water a little more without losing water pressure. I would love nothing more than to discover I need to move up a pitch or two (from the 17) if I can indeed raise the motor up some more.