ZX props for dummies...

[78Staff]

So... will start of by saying I am not chasing speed... well not really :). Just want to make sure I am getting all out of my rig that it can deliver. I keep reading threads and seeing videos of the ZX225 being a 70+ mph rig. My 2016 ZX225 with SHO 225 and 25 T1 prop, is a 65mph rig at best... and typically closer to 60 most of the time.

Slidemaster Jackplate is on dot 9 (as setup from previous owner). At first I though it might be hotfoot adjustment related, b/c it seems the last 25% or so of the throttle range doesn't change anything. But with the T1 at 6100 rpms I see 65 and that's as good as it gets. And I have to be trimmed pretty much right up against tilt range, ie 93-95% to see that, which to me is on the edge of being too much trim, really. More often I am running 5900-6000 and lower 60's.

I know weight, trim, and driving skill as well factor in. And Poles, I have dual PP's. I usually am running with a full tank (44 gal) since I fill up after every outing on the water. I also run solo pretty much all the time. I've played around with weight, but short of practically emptying the boat I'm not seeing any real difference. I'm also running Lithium's now instead of AGM's - not that I expected a speed jump from them, although holeshot is definitely better.

Anyway, just want a sanity check of sorts - what are other ZX225 folks seeing for speed, and any specific setup tips? Thanks...

Also from previous owner...
1...best speed was a few runs over 73 w/30+ gallons of fuel and T gear...
SHO stock prop...the engine is a beast on both ends.

[78Staff]

A few vids from Youtube on ZX225 speed...

[mrdeath]

I don't own a ZX225 so I can't give you any real world numbers, but the thing you said that jumped out at me was 30% trim. Skeeters like the bow as high as you can get it. My ZX200 runs fastest at 95-100% trim. A lot of guys will say trim it all the way up, then bump it down once or twice. 30% is not near enough.

[McQuaig]

I don't own a ZX225 so I can't give you any real world numbers, but the thing you said that jumped out at me was 30% trim. Skeeters like the bow as high as you can get it. My ZX200 runs fastest at 95-100% trim. A lot of guys will say trim it all the way up, then bump it down once or twice. 30% is not near enough.

This is true of my zx200 also (I need 3/4 to full trim for top speed). i checked my gauge in the garage, and with motor trimmed so the cavitation plate is level with the pad (what I call neutral trim) the gauge reads about half trim. So, if your 30% trim is accurate, you are likely not at neutral trim yet and therefore still pushing the bow down, reducing speed and probably not allowing the boat to feel "light", riding on it's tail...my opinion only...

[McQuaig]

Since you say the last 25% of throttle range does nothing, you may want to check the throttle adjustment at motor. This pic (shown at idle) shows the correct alignment marks. The scribe mark should align with the arrow at full throttle. Some people mistakenly adjust it past the arrow until it hits the "bent tab" so the throttle plate opens fully (not correct).
throttle adjust.JPG

[okskeetertzx190]

Also a lot of the speeds people get out of boats don’t have 2 power poles like you mentioned and they often don’t have the extra weight in the nose of the boat from multiple electronics, 360, etc. The added weight in the nose of the boat can make a big difference on performance. A call to Hydro-tech for an ECU flash can help offset added weight lol.

[TxBassfisher]

I had a 2019 ZX225. It would run 67-69 no prob and low 70s on a good day. Set up was on 7th dot and stock T2 prop. It ran best trimmed pretty much all the way up. It sounds like you are not trimming up nearly enough if you are keeping it at 30%. I would try dropping plate to 7th dot and trim up more.

[78Staff]

Ok so when I say 30% trim I'm referring to the digital value from the Yamaha nema feed - it's essentially right at the point before tilt kicks in (tilt kicks in 32%, at least on the trailer :) ). So relative to that I guess I should have said I am trimmed at about 93-95%. When I get to 30-31% (nema scale) I get that nice throaty 4-stroke growl and that's where i see the best performance, but again nowhere near 70mph.

I do have dual poles, and dual 12" units on the bow. I noticed the guy in the vids I posted does not have poles.

I'll check the throttle when I get a chance, need to find someone to press the pedal for me I guess lol.

[okskeetertzx190]

TXbass may be on to something with the 7 dots as well. My 2018 ZX200 came at 7 dots from the factory.

[rctreece]

What is considered dot 9 or 7 on a slidemaster? Are you talking a hydraulic jackplate gauge?

[okskeetertzx190]

The dots are on the side of a manual jack plate that are visible when the inner portion starts to raise up from the outer portion of the jack plate.

[Verkeith]

I had a 2022 ZX225 that would run 71-73 consistently with just me, 1/2 tank of gas, dual Raptors...factory jackplate setting and stock 25T2 prop

[woppercatcher]

I have a 2021 ZX225 and I’ve only been able to get 70mph at WOT a couple times with just myself in the boat and less than half a tank. The RPMs were in line with the performance bulletin as well. Every thing is stock and the prop is new since the cirst one threw a blade. I have to trim the motor as far as I can but then it takes both hands to turn to the left. The thing I don’t like is if I just want to run at say 50 or so I have to trim real high and I get a lot of rooster tail which I believe might have helped throw the blade. With two people I have a hard time getting much more than 60mph.

[78Staff]

I have a 2021 ZX225 and I’ve only been able to get 70mph at WOT a couple times with just myself in the boat and less than half a tank. The RPMs were in line with the performance bulletin as well. Every thing is stock and the prop is new since the cirst one threw a blade. I have to trim the motor as far as I can but then it takes both hands to turn to the left. The thing I don’t like is if I just want to run at say 50 or so I have to trim real high and I get a lot of rooster tail which I believe might have helped throw the blade. With two people I have a hard time getting much more than 60mph.

Mine is same way, boat is hard to turn to left b/c I've trimmed up too much to gain what top end I can... But I don't really have any issue running 40-50mph as you mentioned...

I may drop it down 2 dots, which would make sense as I've pulled close to 200lbs of batteries out of the ass end switching to all lithium. Although I've been thinking about swapping out the SlideMaster for a Bobs Action Jack after the new year (not so much for speed, but for running shallower in Florida) so may just hold off until then.

[utinator]

Have you noticed air being sucked in when you remove the gas cap? These boats are known to have fuel-vent issues. If it can't get air in as you burn fuel, it will collapse the fuel tank. The tank will only collapse so far before the fuel supply gets constrained. Less fuel = less mph. The tank needs to vent so you can get full fuel.

Mine started running about 65mph until I figured out how to bypass the fuel tank vent system. Now, it's back to normal. I'm getting about 68-70mph with a cheapo 4-blade. That's about what it was running with that 4-blade before the fuel-vent issue. I haven't tried my 3-blade yet. The lakes are still low, so I keep the "beater" 4-blade on there.

[utinator]

Here's my video of my boat running up at altitude with no fuel-vent issues. GPS speed is in top left corner of the HDS-9. I was using a 3-blade in this video. https://www.youtube.com/watch?v=bwxjqMJPIn0





Here's running at sea-level:

[78Staff]

I haven't noticed any air sucking in, but will pay closer attention next time.

How much are you trimmed up there at speed? I notice also it doesn't look like you have any stiff steering at speed either...

You're easily 10mph faster than me at 6000 rpm...

[McQuaig]

I haven't noticed any air sucking in, but will pay closer attention next time.

How much are you trimmed up there at speed? I notice also it doesn't look like you have any stiff steering at speed either...

You're easily 10mph faster than me at 6000 rpm...

Different outfit than yours, but mine is VERY hard to steer left at less than 3500rpm with minimum trim. Above that rpm i can trim up and it totally eliminates any steering torque. One thought: You don't by chance have transom wedges installed do you? If so, the extra negative angle would be keeping your bow down even though the trim was at maximum....

[rctreece]

The dots are on the side of a manual jack plate that are visible when the inner portion starts to raise up from the outer portion of the jack plate.

So i just checked mine and it is on the 8th dot. I might play around with it since I added the lithium batteries and lighten the load 200 lbs or so. Thanks

[AndrewM-Fishing]

Where is the transducer mounted? I had a zx202 that should have been low to mid 60's but was only getting low 50's. Turns out the transducer was too close to the line of the prop. Move the ducer and picked up 12mph. Also if that prop is way out of balance that could be causing loss on top end as well.