2018 250 PRO XS performance on z21

[Stl142206]

I have a 2018 nitro z21 equipped with a 250hp Pro XS two stroke, 12in atlas hydraulic jackplate, and 24p fury 3 blade prop.

With 3/4 tank of gas, full live wells and 2 guys I am able to turn ~5650-5700 RPMs and get ~64 mph at WOT. I removed weight from the front of the boat to try to help. I also experimented with a 25p tempest, but it performed worst than the fury.

Are my stats the best performance I can get? Does anyone have experience with trim extenders or transom wedges? Also, my engine is currently under warranty through the white river protection plan, so I obviously would not want to do something that would jeopardize that.

[blacknitro]

Did the boat go faster before?

[Stl142206]

Before what?

[blacknitro]

If that's the speed you always got with a 250, and the Opti is running well, I might be tempted to put a straight edge on the pad of the hull and see if there's a slight hook in the hull. That would also make bow lift impossible. You should be doing a little better than 64 with that boat.

[mactlman]

18 model year was a weaker detuned motor most say from the previous years. might talk to mark at marks propellers and ask about a bravo 1 based prop that is a big heavy hull and the bravos will lift both ends up more

[Bryanmc57]

Have you tried posting in the Nitro forum to get an idea of how similar rigs are running and how they're set up?

[Stl142206]

Thanks guys, and yes I have posted in the nitro forum as well. Guys recommended transom spacers and trim extenders. This year I started fishing larger lakes so needed more gas in the tank first thing. That is why I am just noticing this issue. Plus this is my 2nd year with the boat as I purchased it brand new as a left over.

[Fish Boy]

I have a 2018 z21 with a 2018 250 opti pro xs and have the exact same problem. I've switch out so many props! But with how it's currently running I'm getting best performance from a 23.5 bravo xs. With that being said and many times in the shop and talks with many people it sounds like it is a bad exhaust tuner. My best friend has the exact same boat and year as us and does 71 to 74 we do tops of 64 on a great day and technically our engines are running great per diagnostic tests. So this is currently where I'm at with this exact problem.

[Stl142206]

Thanks for the input! What type of speed and rpms do you get with the bavo xs?

[Fish Boy]

About 5850ish

[Fish Boy]

I don't mind not going over 70 at all it's just knowing that I can't which means there is a problem is what bothers me the most. Hole shot is fantastic, handling is super, low planing speeds are good, in general everything is great except for top end.

[Stl142206]

What is top end speed for you with that prop?

[Fish Boy]

Still around 60 but overall performance is much better than with a fury 4, fury 3, or tempest.

But like I mentioned if you truly want to fix it gets your exhaust tuner checked out.

[JOE54]

LITHIUMS in these boats ???????? unload it and go run it will tell how weight effects performance

[Stl142206]

I can get 67-68 with 1/2 tank of gas no gear no water and one guy

[Stl142206]

and no I do not have lithium batteries

[JOE54]

only 3-4 mph drop loaded is very respectable

[Stl142206]

i would agree, so its the unloaded top end that is the issue.

[lpugh]

Important for us to know what the elevation is with those numbers, 2500 Ft they would be about right, under 1000, you have a problem

[EuropeanAM]

Important for us to know what the elevation is with those numbers, 2500 Ft they would be about right, under 1000, you have a problem

^^^^ Agreed.

If you would, please take a moment to review the Announcements at the top of the Forum, and be sure to provide the Required Info (serial number) when posting. Thanks!


Checked to make sure you're reaching WOT at the throttle plate?

How many hours on the boat?

What trolling motor and other equipment at the bow?

Note: Transom Wedges and Trim Extenders are not approved for use with your engine per service bulletins/literature.