I have 2013 Z9 DC with a Merc 250. When I'm by myself and 1/4 tank I get great lift and run 68mph and turn 6600rpm. Add a person, any person, and I get no lift and run 59 mph at 5900-6000 rpm. I'm running a 25P Tempest+, I've run 24p and 25p Fury 3's with no better success. Any help is appreciated!!!
Last edited by GHawk; 08-12-2020 at 02:56 PM.
6600 RPM's sounds like a bit much. What is your PTP? Is your prop in good shape? Has it always ran like this? Did you just get this boat?
I had a 2013 Z-9 and it ran the speeds you are seeing.....without hitting 6600 RPM. I think max RPM on the 250 Pro-XS is 6200.
Yeah, your tach is boogered up. I heard there is a 5 position dial in back of the tack, adjust it a couple click one way then back to your starting position this fixes some sometimes. this is based off your speeds with a 25 tempest vs rpm. I have gone 76 at 6100 rpm with my 25 tempest plus, but normally 5800-5950 at 68-73 (z8 not apples to apples but, your slip % is super high)
is a pretty steal drop for just adding a passenger, you really need to get all of your heavy stuff in the back two compartments. I store everything back there.
Mercury 250 proxs 2B115089
You would, or should be getting alarms around 61 or 62k rpms. Always felt the Tempest was the right prop for the Z9s. 59 with 2 people seems low, not too mention some big slip numbers.
I think you need to get that tach confirmed and reading correctly. And you should be 3-3.5 below pad.
Bryan McDonough
2023 Nitro Z21 XL
Nitro Team
Do you happen to have the Merc Vessel View app? If so, check your rpms on it because it reads straight from your computer. You can verify your tach that way.
2011 Nitro Z7
2011 150 Mercury Optimax
In the original post I was off by 1000 rpm. Not sure what I was thinking when I posted. Single 68mph at 5600rpm with good lift, add a partner its 59 at 4900-5000rpm and no lift. That's with Vessel View and at 3.5 below pad.Originally Posted by GHawk
Bravo 4 in 25 p
Mercury 250 proxs 2B115089
That's crazy that you lose 1300 rpm and 9 mph with adding one additional person. I never experienced loses like that with my setup and it was very similar to yours with one exception. The prop that I had was worked by DAH in Wisconsin. The previous owner of my boat put in a fair amount of time trying to hit the 70+mph mark in a Z-9.
If you do some digging in the Nitro forums you can find that info.
U need someway to verify your RPMs. Maybe you have a power pack issue, those can be random.
Bryan McDonough
2023 Nitro Z21 XL
Nitro Team
Reply With Quote