[jsburkey21]

I have a 1998 Z202 with the carb 5.7. Currently i have a 21 pitch SS vengence prop on it, and it will hit 58-60mph. My RPMs read 4000. This seems a little low, but my question is if i get a 19 pitch (need better hole shot for wakeboarding) how bad will my top end suffer? Is this low of an RPM normal with this prop, motor, boat combo? Could my Tach be bad??

[mikeyt]

First off i'm gonna suggest that you read the 'Sticky' at the top of this forum. It will give you the basics on props/pitch/WOT rpms etc and should answer all of your questions.

Are you sure about that 60mph? Is that GPS or via your speedo? As for the tach, there is a small dial on the back of it marked 4 - 6 - 8 cyl. Give the dial a few spins & then reset it at 8 cyl. Sometimes a little bit of corrosion affects their operation.

[jsburkey21]

Thank you for the answers! They really helped out. Ill try the tach thing, and my speed was calculated on my speedometer not GPS. I have been looking and can't find a "CUPPED" prop like the one on the sticky. Ill take the boat out again this weekend with a GPS and make sure my tach is reading correctly.

[jsburkey21]

Does anyone else have a z202 that can share their prop size, pitch, speed, and rpms?

[DCB_MINDED]

That RPM sounds a little low to me, but your outdrive gearing could be different.... I know 238 (with the 5.7) had a 3 blade 19" on it when I bought it and it was turning 4100 at 41MPH, but it was a dog out of the hole. I dropped to a 17" highfive for better holeshot and it runs 4450 at 39MPH.

P.S. 58-60 sounds pretty high to me, the speedos on these things were not accurate at all. Try to get a GPS speed

[mikesnowman]

i had a 96 Z200 5.7 alpha, 2 barrel carb. I had a 19 pitch rapture SS and it would spin about 4800 at 50 mph GPS. I tried everything to get more top end. Could not do it. I personally think the 21 is too much for that motor as I tired several and the rpm's came way way down in the low 4's. I was happy with the 19 for pulling and it would do 50 all day long fully loaded. I was going to go with a 4 blade 20, but traded for a big block. Good luck!

[mikeyt]

The 19" pitch prop is pretty much standard for most of our Alpha One / Brave One applications so that would be a good place to start.