1981 Nautique with 1200 pounds of ballast and 4 passengers + 1 rider at 24 mph = 2800-2900 rpm.
unweighted at 24 = 2400 rpm.
Kind of a different situation I know, but I thought I'd add. though I won't tell you the fuel use, I might make you guys with your nice big V-drives mad ;-) (I want a V-Drive someday too)
What's important is not only the RPM's while pulling, but also how much the tach climbs when you hit it. More RPMs mean more horse power developed, so better whole shot.
You know what, I'm actually not sure what the prop is. I believe that it's actually the stock brass prop. It's a 3 blade and it's intended for skiing (1981=no wakeboarding yet). I think it's more of a speed prop, but hole shot is still fine, even with tandem riders and ballast in place. I will be looking to get a 4 blade at some point to up the rpms in the hole shot a bit and ease the load on the engine.
Brian, the CNC props recommended for our boats are the ACME 540 and 542 for heavy loads, I'm looking into one of those right now and want some feedback from someone who has tried them both.
Could you send me a pic on your wake when loaded down?