When I first looked at your picture, I thought that mine is in the same place and it doesn’t cause me any trouble. Then I realized that I mounted my transducer on a Stern Saver and mounted up higher in the cavity where it’s only in the water when I’m off plane. I’m not sure whether or not your skimmer transducer would cause that much drag or not?Originally Posted by Kjensen75
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Don't worry Ma'am....
I'm only here for the Bass.
i would expect the spray to be coming out well behind the drivers seat. I would probably throw a different prop on it and see what happens
Might not be trimming up enough.
Eric Goff
2019 Nitro Z20
2019 Mercury 250 Pro XS 4s
model #12500033A
SB590181
If I am reading this correctly, you don't know what you are measuring or the importance of prop-to-pad. If the bold was in fact true, your PTP would be somewhere around 13 inches, which is impossible. Your PTP should be somewhere around 3 1/2" or less with water pressure safely above 12 psi.
I saw this but don't think it was measured correctly because he would need to have backed the motor off a loading ramp to trim down below the trailer wheels that much.
Yeah, I would like to see pics of the motor's current position with measurements to get a better understanding. This boat should be going strong with a 250. No way a little transducer is slowing it down 10-12 mph. It has always been a PITA to diagnose these issues over the boards. More often than not it is a simple adjustment; the need for more seat time, or just lack of understanding the physics behind weight, load and resistance. i would gladly FaceTime with to OP to get him set up right.
I think the prop shaft is to deep.
you have a hydraulic jack plate right?
if the cavitation plate is 5 1/2” below pad then the prop shaft is to deep.
If the prop shaft is to deep it will cause to much drag from lower unit.
drag from lower unit to deep will chop off mph
prop to pad is normaly close to 3 1/2”
Are you measuring from the rear setback or actual boat pad?
I hit 74.0 Saturday with two guys and a tourney load in my z21 with a 250hp so you got something up....
I am thinking hooked hull, my input to this issue. I sure hope he figures it out to enjoy the boat to it's fullest.
HELL yes you should be hitting 70+. I have the same boat with a 225 pushed by 23P Fury and I’m hittin 67 at nearly 5500 with a manual jack plate.
What’s your PSI at WOT?
Id have a certified Merc Tech change your impeller, LU oil, engine oil, and oil filter. My impeller had year 2019 on it and I ordered my boat in FEB of this year. It was not installed properly and the integrity was very flimsy. Was getting 10 psi tops, now it’s ranging correctly at 15-17 psi wot. After the change, I felt the difference with mid range speed and top end.
I think a 23P Fury would spin better for you.
If you haven’t had your hot foot checked and had a G3 check to see if you’re 100% linear, I would. I was at 94% at delivery.
Those are hellacious numbers especially for a Z21.I hit 74.0 Saturday with two guys and a tourney load in my z21 with a 250hp so you got something up...
I do think 74 is very possible in a Z20 with one person though. I can hit 74gps with 1/2 tank of fuel, by myself, and I also have 2 talons...
By the way, has anyone asked the OP if his speed is GPS?
Last edited by KCLOST; 09-14-2021 at 07:34 AM.
Layton Strong
Nitro State Team
This would be my best guess also. I had a z7 that I chased the exact same issue on for over a year, before the dealer finally mentioned that I might have a hooked hull. I took it to 3 Mercury mechanics, and I changed out props, and I added a jack plate and I was super frustrated. Nitro took the boat back and tried to fix the hull, but when I put it back on the water to test after they had reworked the bottom of the boat, it still was hooked, so Pro's Choice actually reworked the hull and finally fixed the issue. The one thing I would say is, the hull was not coming out of the water, knowing what I know now, it was pretty obvious it was a hull issue and not a motor issue, but at the time, I had never heard about a hooked hull.
There may be a unicorn z21 or any specific boat but we wouldn't have to ask such a ridiculous question if the manufacturer would quit installing that trash system on a boat. Fuel gauge, water pressure gauge, trim gauge and a tach are all we need
Mercury 250 proxs 2B115089
My apologies.....I just realized I typed 74.0. it was 72.0. I'm very pleased with the setup. Came this way from factory.
Unfortunately that seems like a pretty good possibility, unless his trim and height settings are way off he’s getting way too much drag it sounds like. I definitely wouldn’t start throwing props at it, I think dealers like throwing that “solution” at it as a way of getting out of doing anything.
2020 Nitro Z20 Pro Package
I don't think you would find any of the later model z boats with hooked hulls.
2020 Nitro Z20 250 Pro XS
How long is it taking you to get to 61? Or how long are you sitting at 5700 rpm and staying at 61 mph? Users who report speeds of 75-77 usually takes about 1-3 minutes to get to that speed and is not immediate.
Not sure on the jack plate height but with the motor trim when you are at 60 mph that boat loves as much trim as you can give it.
I'd move the transducer to see if that does help.
Bryan McDonough
2023 Nitro Z21 XL
Nitro Team
I have a 2021 Z20 with a 250 4 stroke. I had a 2 day tournament this weekend and I paid attention to the spray when I was fully trimmed. The spray is no where close to the drivers seat, it is on the back corners. I am running 73-74 with a partner, half tank of gas, and empty livewells. With Full tank of gas and full livewells, we are hitting right at 70. I have 2 Talons on the back.
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