Picking A 4 Blade Prop For My 4.3L Cuddy

[alldodge]

On the initial runs of the day when trimming the boat up, it seemed like the RPM would jump and the speed would drop. I am guessing some type of slipping?

The 4 blade prop gives more lift and will ventilate easier in chop

4 Bladed Nemesis 14" with a 21" pitch WOT: ~39MPH @ ~4200RPM via boat's pitot and tach

Your about at 15% slip w/o gps readings

owner accidentally swapped the out drive for one with a 1.62.

Probably not, but if it is, then your slip goes up to 24%

2) Is my 18 year is putting out less power than it use to?

Maybe, but this would take compression and leak down test. If your boat gauges are close to accurate then your not doing to bad

3) Should I just buy a 19 pitch and give it a shot?

I would see if you can borrow a good 3 blade 21 or get your old one fixed
Then also borrow a 4 blade 19. Many prop shops let you exchange props for trial. You buy one and then can change to different ones