Hi
I have donzi 33zx 2004
525x2 racing
30 bravo 1 propeller
Top speed 78mph

I*read*E-site*there are boats*bigger than*the*size*of*my*boat,such*as*engine*type*and*s trength*and*speed*more*and*Ithink*due*to*the*size* of*the*propeller What*size*suitable for*myboat*propeller

i have the 500efi motors and am running 28 4 blades and last year i got 82 out of it on gps. so u should be faster then me alittle bit. u might be over proped. i was thinking about going up to 30's and was told that i would be alittle better out the hole and a little better cruse speed but might lose topend. if u r looking to up your top end mabe try some 28's and u might gain some then if u still want more have them labed. that is my next step when i have the extra cash.

I have a 38zx and have 500efi, with 28p 4 blade and get 72mph at 4800rpm

525 efi or 525 SC..?

I think you have that a little backwards. If you can turn the 30s they should give you more top end, but slower to plane.

i might be worng but im prity shure that is what i was told by brett at bblades alittle whyel back

525efi mercury racing blue engine

what was your rpm at wot?

5000 rpm trim 3 speed78
5200 rpm trim 5 speed 77

Mach, I also am running 28 4 blades with 500 efi on my 33zx. I'd love to see 82! I'll know next weekend