2014 nitro z8 speed issues.

[Pfishnfool]

Hello everyone,
I’ve got a 2014 nitro z8 w/ mercury 250 pro xs. Tempest plus 26 prop. Bought it in February and new powerhead in may (ouch). 2 guys half a tank of guys I can get 63 at 5800 rpm’s. Always had big rooster tail and I don’t feel like I’m getting the bow lift that I should. I’ve moved the jackplate up and down anywhere between 2 1/2 ptp to 5. Lower helps lift and rooster tail but hurts speed and rpm’s. Higher helps rpm’s but not much speed gain if any after a point. Rooster tail gets worse. Blows out on takeoff badly as I get higher. Changed vent plug size to help this problem. All I know to do is try some different props. Should I go to a 27, 25 or possibly another brand? Any other suggestions are welcome as well. Thanks in advance!!

 

[Chobeemauga]

Welcome to the site!
The rooster tail should not go higher than you engine cowling. It is trimmed to high and you are losing power. May want to check you motor height- there are several threads on this. Basically you want the center line of the prop shaft as close to 3inches as you can get it. Sounds like you have a hydraulic jack plate so it should be easy to adjust. Check the threads on the procedure for measuring.
That's about all I can help with. Hopefully a more knowledgeable member can speak to your boat and HP and point you in the right direction on props.
Best of luck!

 

[Pfishnfool]

It’s a manual jackplate. I understand the prop to pad measurement. Nothing with jackplate adjustment has really helped. I’ve also played with the trim to bring the rooster tail down but don’t gain anything from that either. It does reduce rpm’s. I’m more interested in prop selection for this setup. Thanks for the reply.

 

[FastZ8]

Hello everyone,
I’ve got a 2014 nitro z8 w/ mercury 250 pro xs. Tempest plus 26 prop. Bought it in February and new powerhead in may (ouch). 2 guys half a tank of guys I can get 63 at 5800 rpm’s. Always had big rooster tail and I don’t feel like I’m getting the bow lift that I should. I’ve moved the jackplate up and down anywhere between 2 1/2 ptp to 5. Lower helps lift and rooster tail but hurts speed and rpm’s. Higher helps rpm’s but not much speed gain if any after a point. Rooster tail gets worse. Blows out on takeoff badly as I get higher. Changed vent plug size to help this problem. All I know to do is try some different props. Should I go to a 27, 25 or possibly another brand? Any other suggestions are welcome as well. Thanks in advance!!

I have the exact same boat. I put an Atlas hydraulic jack plate and it helped a ton. Had the same prop and it was garbage. Put a 24 Fury on and at 5800 I run 72 all day with a partner, fuel and tackle

 

[Pfishnfool]

I have the exact same boat. I put an Atlas hydraulic jack plate and it helped a ton. Had the same prop and it was garbage. Put a 24 Fury on and at 5800 I run 72 all day with a partner, fuel and tackle

Thanks for the reply. I love the boat but garbage is a good description of driving lol.

 

[Kirby Wilson]

You have around 23% prop slippage. The roster tail higher that the motor is usually an indication that the motor is too high for that prop. The prop you have is calculates out to a speed of 72 mph at 11% slippage.
Not a prop designer but have been around prop designers and some of the best prop persons for over 40 years and have helped prop out many of a boat.
I had the same problem with a Z-7 w/ 200hp. The Tempest plus would slip, especially when turning. Went with a 24 pitch Fury and the boat preforms better.
Every Z-8 boat will run differently bast on the hand laid hull and the way it is loaded. Boat dealers and Manufactures have a general prop selection that will perform on their boat model.
A Mercury Fury 25 Pitch will allow grip better even though it has a smaller radius and may not give the lift you want.
A Trophy Plus four blade prop is designed for a heaver load boat and will give you more lift.
There is a several variations that can come into play. Anymore it is hard to find a prop shop that will meet you at the lake to prop out a boat to its peak performance with different props.

 

[Pfishnfool]

You have around 23% prop slippage. The roster tail higher that the motor is usually an indication that the motor is too high for that prop. The prop you have is calculates out to a speed of 72 mph at 11% slippage.
Not a prop designer but have been around prop designers and some of the best prop persons for over 40 years and have helped prop out many of a boat.
I had the same problem with a Z-7 w/ 200hp. The Tempest plus would slip, especially when turning. Went with a 24 pitch Fury and the boat preforms better.
Every Z-8 boat will run differently bast on the hand laid hull and the way it is loaded. Boat dealers and Manufactures have a general prop selection that will perform on their boat model.
A Mercury Fury 25 Pitch will allow grip better even though it has a smaller radius and may not give the lift you want.
A Trophy Plus four blade prop is designed for a heaver load boat and will give you more lift.
There is a several variations that can come into play. Anymore it is hard to find a prop shop that will meet you at the lake to prop out a boat to its peak performance with different props.

Thanks

 

[Bass Lush]

Hello everyone,
I’ve got a 2014 nitro z8 w/ mercury 250 pro xs. Tempest plus 26 prop. Bought it in February and new powerhead in may (ouch). 2 guys half a tank of guys I can get 63 at 5800 rpm’s. Always had big rooster tail and I don’t feel like I’m getting the bow lift that I should. I’ve moved the jackplate up and down anywhere between 2 1/2 ptp to 5. Lower helps lift and rooster tail but hurts speed and rpm’s. Higher helps rpm’s but not much speed gain if any after a point. Rooster tail gets worse. Blows out on takeoff badly as I get higher. Changed vent plug size to help this problem. All I know to do is try some different props. Should I go to a 27, 25 or possibly another brand? Any other suggestions are welcome as well. Thanks in advance!!

I had a similar problem but my engine was not turning above 5500 RPM. I have a 25P fury. I contacted my original dealer and found that my former local dealer had switched during service. I was supposed to be running a 24P.
The 27P would slow you down and drop your RPM. So going to a 25P would increase your RPM and speed

 

[Pfishnfool]

I had a similar problem but my engine was not turning above 5500 RPM. I have a 25P fury. I contacted my original dealer and found that my former local dealer had switched during service. I was supposed to be running a 24P.
The 27P would slow you down and drop your RPM. So going to a 25P would increase your RPM and speed

Thanks

 

[FastZ8]

Thanks for the reply. I love the boat but garbage is a good description of driving lol.

Actually, I was referring to your prop, man. The Fury 24 or 25 will make a huge difference. When I test drove the boat new, I just assumed that Nitros were slower than my Triton until the dealer switched out my tempest and put a fury on it. Don’t worry about how I run a rig, been doing it for a minute or two.

 

[Pfishnfool]

Actually, I was referring to your prop, man. The Fury 24 or 25 will make a huge difference. When I test drove the boat new, I just assumed that Nitros were slower than my Triton until the dealer switched out my tempest and put a fury on it. Don’t worry about how I run a rig, been doing it for a minute or two.

Thanks again. I’m not sure what that last sentence was for. I was talking about my boat driving like garbage and meant your description was spot on. I never meant anything about how you run your rig. My bad if it didn’t come across the way I meant it.

 

[Allen Dronsfield]

I have this 2019 Z20 Pro, 225 ProXS I have a 10" Atlas hydraulic jack plate with the 23P Fury, chine walk is always an issue starting at 68 mph the boat topped out at 78 mph without the plugs. One thing I found interesting was watching youtube videos. One video was based on weight distribution, that alone helped a lot. Considering I fish 90% or more by myself I adjusted weight accordingly. I always keep my fuel tank full, 50 gals. Adding another person to the boat mainly affects the hole shot and chine walk. The hole shot is explosive, it nearly come out on plane. My jack plate is normally set at about 2 to 2 1/2", we had the Bassmasters here on the Harris Chain this year and they had demo rides so I got to do that along with pros Dan White and Johnny Morse, they both agreed that 2 to 2 1/2 was the most setting with Nitro pros. My advice is start with weight distribution, distribute the weight accordingly for yourself only in the boat.

 

[jerry shack]

Thanks again. I’m not sure what that last sentence was for. I was talking about my boat driving like garbage and meant your description was spot on. I never meant anything about how you run your rig. My bad if it didn’t come across the way I meant it.

I have a 25 Fury I am selling if you go that way, they make a big difference in how the boat preforms. Even loading on the trailer.

 

[FastZ8]

Thanks again. I’m not sure what that last sentence was for. I was talking about my boat driving like garbage and meant your description was spot on. I never meant anything about how you run your rig. My bad if it didn’t come across the way I meant it.

No worries my friend. I hope it works out for ya man!