Cavitation at 4,000 rpm

[Bamby]

Glad to hear the new prop fixed it. Yes, I think you are probably spot on. Unload the family, ditch the grill and run it unloaded. I bet you'll be over your 6000 R's and probably running in the low to mid 40's. Feel the wind in your hair at WOT and you'll be driving a Baja next summer!

Actually IMHO we actually don't know if it's fixed. Yes the RPM's are better but in this run the load was different from the first run.

Water was choppy, had 8 adults of average size 4 in front, 2 in middle seats, and 2 on rear loungers.

In this last run the OP didn't state seating position of the occupants in the boat. But there is still a chance that all passengers were effectively seated in the rear of the boat and the condition could still exist. But IMO the best advice for getting it right is this:

Unload the family, ditch the grill and run it unloaded.

But here's to hoping you've actually corrected the problem.

[justfishing]

I would prop it for how you normally load the boat. If that is with family and coolers then try to get a prop that will get you the extra 500rpms. There will probably times when you are loaded heavier than normal. You want you prop to hit be able to get as close to the recommended range as possible even when heavily load.