[ual777mech]

thanks it has a
7.4 454 engine
capt choice adds speed.
great and fun boat

[mark43]

Hi Everyone,

Does anyone think it is weird that with a 250hp 5.7L and Bravo III in my Z210, I am only able to get 48mph with three adults in the boat? I would have thought I could get up to 52-55 mph with that set-up. My RPMs are right where they should be. Does this appear reasonable? If not, does anyone have any suggestions?

Thanks!

[Mariah350]

Originally Posted by ual777mech

1996 mariah z210 limited edition
7.4
2 people smooth water 62mph.

Just wondering if that speed is on the speedo or Gps?

thx

[mark43]

It is on my GPS, so it should be spot on.

[jarwiebe]

Just got home from a afternoon of boating.
WOT of 4,800
Boat speedo showed 52 (forgot my GPS at home)
Equates to 11% slip if speedo is correct.
Calculated speed if slip is 15% would be between 48 and 50 which sounds more right.


1996 Z210 Shabah
5.7LX MerCruiser
Alpha 1 with 1.47 gears
14 1/4 x 19 Aluminum Turning Point prop
80 lb smart tabs set at middle setting
3 adults
3/4 tank of gas

It seemed like I wasn't planning as high as I should be so maybe need to try a lighter setting on the tabs which might give me an extra mile or two on the top end.

[jarwiebe]

Just ran another test, 3 adults, 1/2 tank of gas, water smooth as glass.

51 MPH GPS
53 MPH on boat speedo
4,700 RPM
smart tabs set on the second hole from the lightest setting.

[Climateeast]

I have a 98 shabah 454 mag mpi with bravo 3 and I'm running 70 gps. 26 pitch props that have been cupped

[PlumLazy]

Figured I'd chime in even though this is a fairly old thread.
My very low hour '94 Shabah Z211 with stock 5.7 4-barrel and Bravo III and thru-hull exhst., and the stock quicksilver 24p props GPS'd at 57 mph in light chop. (speedo does not work) With over 10 gal of fuel and two skinny adults. lol. Top speed was with the trim 1/8 up on the guage.
I just installed a K&N filter and am hoping with less fuel and just me it will go 60... just so I can say I did it once. lol. BTW... I lost track of the RPM when I was watching the GPS, but was a tick over 4500rpm I beleive. When we tested it before purchase with 3 adults and a full tank (30gal?) it GPS'd at 54mph.

[mustang67gt1]

My 1996 shabah Z210 with 5.7 runs 53-54 mph with wife, teenage daughter & boyfirend, 12 yr old daughter and friend. This is with the 2bl motor, electric marine fuel pump, K&N filter and aluminum prop. Next year I am changing over to an aluminum manifold, 4bl carb, Mallory pointless ditributor and hopefully will get to the 57-59mph....I have had this boat out once so far just purchased end of last year. Seems to have great power all the way through Owner called me a week later and try to purchase back? I bought for $7800 nice condition.

[Frostyz210]

Originally Posted by mustang67gt1

My 1996 shabah Z210 with 5.7 runs 53-54 mph with wife, teenage daughter & boyfirend, 12 yr old daughter and friend. This is with the 2bl motor, electric marine fuel pump, K&N filter and aluminum prop. Next year I am changing over to an aluminum manifold, 4bl carb, Mallory pointless ditributor and hopefully will get to the 57-59mph....I have had this boat out once so far just purchased end of last year. Seems to have great power all the way through Owner called me a week later and try to purchase back? I bought for $7800 nice condition.

I know this is an old thread but what was it you were running for a prop? what did you end up going with? and what were the results? I have an identical setup but can only get it to run 45 on GPS by myself with the 3 blade aluminum prop on it that over revs to 5100 father in law just brought home a brand new cobalt and I want to try and out do the 52mph that will do thanks