severe porpoise??

[jwbbuck]

First time out in a used boat. 23 Warlock with short Bob's nose cone, 530hp 502 Chevy, Bravo. I put a 27 Hydromotive IV 4-blade and had severe porpoising that I could not "drive through" with any power. The porpoising came on at mid-range speeds 30-40 with anything other than the drive tucked all the way in. Should I try a 3 blade Mirage? or Bravo?

[bajaboater502]

I ran a hyromotive 26 pitch four blade until yesterday on my baja 272, my boat will porpose in calm water under 3/4 to full throttle runs when all trimmed out. I know a hook in the hull will cause this and had mine check and the wasn't one. I was told that my boat will tend to do this in calm water because of its length. It is almost like it is looking for the next wave to run through. When I get her out in to some chop it runs faster and no porpoise because there is less friction on the hull. I got a bravo one 4 blade 28 pitch and ran it yesterday and it performed better and I did notice a little less porpoising than the hydromotive.

[272 baja 502]

i have a 2000 baja 272 and i get it at 3/4 to full throttle also. im running a marage 3 blade 23 pitch. if i put in just a touch of down in the tabs it goes away. I was told the same thing that the boats are very balanced and all of the 272's do this. I left the tabs in the position that keeps it runing flat when i pulled it on the lift and they were almost level with the bottom of the hull just barely down.
i hope this helps

[272 baja 502]

question to bajaboater502 is your engine stock or have you upgraded any. i was thinking of going to a 25pitch prop but didnt know if it would pull it or not. its interesting that you can run a 26 and a 28. i can get 68 out of mine on a good day. how fast are you running ?

[jwbbuck]

I've heard (and seen some data) saying the Hydromotive are underrated (a 26 is more like a 28). I think I'll be trying a 25 Mirage on Friday and may leave the tabs set just below parallel and then move them up to see what happens (no tab indicators).
Thanks for the input.

[Quality Time]

I've heard that the Hydromotives provide more stern lift than others which can result in porpoise. Check for hook and try another prop.

[Essex502]

We have a much smaller 21' Essex that came with a 23P Mirage Plus 3 blade...the boat ran like it was on rails but always hit the rev limiter at WOT...tested for several trips a 4 blade 24P Bravo 1 and experienced porpoising and chine walking at very little trim at various. Went to a 25P Labbed Mirage Plus and we were back to driving like on rails, no porpoise and no chine walking.
I'd say - try a 3 blade it might be right for your hull.
Just my $0.02-1/2 cents worth.

[Havasu Hangin']

The more rake a prop has, the more bow lift. A cleaver (no rake) is the other end of the spectrum (stern lift).
More diameter will create more lift. I'd try a 3-blade.