I recently acquired a 2007 Nitro 591 with a 150efi. Total of 75 hours on boat and motor. Motor was checked and everything is firing like it should. It came with a Tempest 21p. It had a hard time getting on plane but when it did it would run like a scalded ape. I had the largest PVS plugs in the prop but it just wasn't spinning up fast enough to get on plane and would hold only 4800-5000 RPMs at WOT. I tried a 13.5" Laser 2 24p that a friend of had laying around. The laser spun up great, but would cavitate at about 5000 RPMs when getting on plane. I would say that despite the cavitation the hole shot was improved over the Tempest due to the RPMs. Once on plane WOT was about 5600 - 5800 RPMs but top speed was only about 54 mph vs 63 with the Tempest. Trying to figure out what type of prop I need. I'm thinking something like the trophy plus since it's smaller than the Tempest, but with the PVS plugs I can adjust how much the water is aerated around the prop to control cavitation.

Tempest
4800 - 5000 RPMs WOT
63 MPH

Laser 2
5600-5800 RPMs WOT
54 MPH

Those numbers don't look right, a 21p should be red lining on that motor!

Try removing plugs completely, 1 at a time & test each time you make a change. It may improve holeshot but still should be more rpms at WOT as plugs have no effect on upper end.

I took one out of my Tempest and it cavitated pretty bad on take off

I think it's more prop dia than pitch. The Tempest is a 14 5/8" prop so it's larger and has more mass to get spinning

I have an old 1979 carbed 150 Black Max on a 18.5 foot Nitro that will turn a 14 1/2" 21P prop at 6000 rpm with a great holeshot but won't get on plane with a 24P Laser 2.A 23P Tempest Plus is a bit too much for it, bad holeshot and 5200 rpm WOT. Turns a large diameter 19P prop at 6300 WOT, that is why I questioned the 21P Tempest numbers....

Thanks for clarifying, it may as well be something else going on.

I went from Tempest Plus 23P to a Trophy Plus 4 blade 21P and have 3X better hole shot and may have picked up 1-2 mph. Max RPM is the same @5600. Tracker Avalanche 18DC 150 EFI Merc. Mid range acceleration with the Trophy 21P is lots quicker and will run on pad at 10mph slower the the Tempest 23P