Another 540 prop question

Message Topic Search Topic Options Post Reply Create New Topic Printable Version Translate Topic

   Really just looking for opinions on what I should do with this 540 prop.  It's on my 81 Nautique w/351w, basically stock except for an electronic conversion kit.

The prop is awesome for pulling anything out of the hole but I think it's reving too high.  I had the boat out yesterday with a GPS so we could get my speedos calibrated.  WOT the boat is running 49 mph turning 4800 RPMS.  Sounds like a bit too many revs.  The boat screams but I won't leave it there for more than a real short burst.  

If I send the prop back to ACME can they cup it & will that have the same effect as adding a 1/2 degree more pitch to it?  I'm thinking I could slow the revs down with the added cup or pitch but not lose too much top end.   

What are some of your speed and rpm results with this prop and boat/motor combo?  

Author	Message Topic Search Topic Options Post Reply Create New Topic Printable Version Translate Topic
81nautique Members Profile Send Private Message Find Members Posts Visit Members Homepage Add to Buddy List Grand Poobah Joined: September-03-2005 Location: Big Rock, Il Status: Offline Points: 5771	Post Options Post Reply Quote 81nautique Report Post Thanks(0) Quote Reply Topic: Another 540 prop question Posted: August-21-2006 at 5:57pm
	Really just looking for opinions on what I should do with this 540 prop. It's on my 81 Nautique w/351w, basically stock except for an electronic conversion kit. The prop is awesome for pulling anything out of the hole but I think it's reving too high. I had the boat out yesterday with a GPS so we could get my speedos calibrated. WOT the boat is running 49 mph turning 4800 RPMS. Sounds like a bit too many revs. The boat screams but I won't leave it there for more than a real short burst. If I send the prop back to ACME can they cup it & will that have the same effect as adding a 1/2 degree more pitch to it? I'm thinking I could slow the revs down with the added cup or pitch but not lose too much top end. What are some of your speed and rpm results with this prop and boat/motor combo?
	You can’t change the wind but you can adjust your sails

79nautique Members Profile Send Private Message Find Members Posts Add to Buddy List Grand Poobah Joined: January-27-2004 Location: United States Status: Offline Points: 7872	Post Options Post Reply Quote 79nautique Report Post Thanks(0) Quote Reply Posted: August-21-2006 at 6:02pm
	that's not to much rpm for that motor you should be fine adding some cup is the way to go just tell them what rpm your at and that you want to knock off 300-400rpm's and be around 4400-4500

81nautique Members Profile Send Private Message Find Members Posts Visit Members Homepage Add to Buddy List Grand Poobah Joined: September-03-2005 Location: Big Rock, Il Status: Offline Points: 5771	Post Options Post Reply Quote 81nautique Report Post Thanks(0) Quote Reply Posted: August-21-2006 at 6:19pm
	79, I'm hoping that that will knock the rpms down at skiing speeds too because there's a big trade off to this prop. Awesome Power=lousy fuel economy. This thing has turned into a fuel pig to the point where I'm going to swap out my old 13x13 or even my 13x14 when we're going cruising and just use the acme for skiing.
	You can’t change the wind but you can adjust your sails

79nautique Members Profile Send Private Message Find Members Posts Add to Buddy List Grand Poobah Joined: January-27-2004 Location: United States Status: Offline Points: 7872	Post Options Post Reply Quote 79nautique Report Post Thanks(0) Quote Reply Posted: August-21-2006 at 6:26pm
	it will bring it down accross the board but not that much, do you know what power valve you have in the carb?

81nautique Members Profile Send Private Message Find Members Posts Visit Members Homepage Add to Buddy List Grand Poobah Joined: September-03-2005 Location: Big Rock, Il Status: Offline Points: 5771	Post Options Post Reply Quote 81nautique Report Post Thanks(0) Quote Reply Posted: August-21-2006 at 6:30pm
	I put a 6.5 in it this spring with the rebuild
	You can’t change the wind but you can adjust your sails

79nautique Members Profile Send Private Message Find Members Posts Add to Buddy List Grand Poobah Joined: January-27-2004 Location: United States Status: Offline Points: 7872	Post Options Post Reply Quote 79nautique Report Post Thanks(0) Quote Reply Posted: August-21-2006 at 6:33pm
	you might try a 2.5 to keep it out of the secondaries more.

Another 540 prop question

About CCF

Donate

Partners

Contact