Help needed to improve top end speed 2010 Nitro Z8 225 Opti

[johnw91]

Hey guys,

I just purchased a new to me 2010 Nitro Z-8 powered by a 225 Mercury Optimax. Boat has a 10 inch slidemaster jack plate. Prop to pad is 3.5 inches currently. I am running a 25p tempest plus. Boat gets on plane really good, and handles good at moderate speeds. Top end that I have been able to get with an empty boat, 1/4 tank of gas and two people is 66.5. Now that I have her loaded with gear, 4 agm size 31 batteries, and two people I am looking at 63.5 as my fastest and thats at 5400 RPM. I know raising the motor will help increase speed, but how high do you think I need to go? What should the minimum PSI be on this motor? How much will raising the motor affect my hole shot? Does anyone else have a similar set up and if so, What kind of speed are you getting? Thanks a bunch !

[Flippin 416]

Is that a Pro-XS or regular Opti? What is the max rpm for that motor? Your RPMs seem a bit low.

[johnw91]

It's a regular optimax. Not sure on max rpms I'll have to look at the owner's manual and see if it says.

[jlittle1274]

I have the exact setup except I have the Pro-XS. The maximum speed I have ever got was 67.5 MPH. I consistently run 65 fully loaded. The only difference is I run the 24P Fury...I do have a 25P tempest plus but the hole shot is better with the Fury with the same top end speed. The majority of my time running the lake is at 50 - 55 MPH so I have not found a reason to tweak with it alot. My PTP is at 3.5 inches and my RPM at WOT runs around 5600 with about 15 lbs of PSI. If you do decide to drop the PTP keep us informed...I may do the same if you have good results. Good luck!!

[Lkmbjb502]

I have a 2011 Z8 with a 10" SlideMaster and until recently running a 225 ProXS - 25P Fury 3 - no poles/Talons but a ton of gear - 36v TM and series 31 Cranking battery - and sometimes 2 consoles. The best I ever saw was just over 70 at about 5900 - weight in the boat always seemed to be the issue for me (too much crap), as the season went on and I added more and more to the boat it would gradually loose speed, at the end of the Season I would clean out the boat and run light for the Fall finding most of the speed I lost throughout the Spring/Summer. Most of the time with 2 guys and loaded with Fuel/gear - mid-60s was the deal. I never moved my plate as ultimate speed wasn't my goal. The last year/18 months - my motor seemed to loose a little speed that never returned, at the same time started idling poorly - tried a bunch of stuff - with multiple trips to dealer - no luck - and at about hour 615, the power head blew. A new leftover 2018 Optimax 250ProXS with an Atlas is waiting for break-in (wanted a new 4S but didn't want to wait and found a deal on this leftover).

Good luck - hopefully you like your Z8 as much as I have liked mine.

-Jonathan

[8man]

I have the exact setup except I have the Pro-XS. The maximum speed I have ever got was 67.5 MPH. I consistently run 65 fully loaded. The only difference is I run the 24P Fury...I do have a 25P tempest plus but the hole shot is better with the Fury with the same top end speed. The majority of my time running the lake is at 50 - 55 MPH so I have not found a reason to tweak with it alot. My PTP is at 3.5 inches and my RPM at WOT runs around 5600 with about 15 lbs of PSI. If you do decide to drop the PTP keep us informed...I may do the same if you have good results. Good luck!!

i have a 2010 Z 8 225 pro xs opti. hydrolic jackplate run a 26p fury. top end 2 guys loaded 5600 rpm 68mph. by myself with my gear. 5600 70-71. But I am getting rid of mine because of hull issues.
have blisters were riding on bunks and cracks in transom and hull. they will fix cracks but saying blisters are a Manufacture defect. And Nitro will not cover because I am not original owner

[johnw91]

i have a 2010 Z 8 225 pro xs opti. hydrolic jackplate run a 26p fury. top end 2 guys loaded 5600 rpm 68mph. by myself with my gear. 5600 70-71. But I am getting rid of mine because of hull issues.
have blisters were riding on bunks and cracks in transom and hull. they will fix cracks but saying blisters are a Manufacture defect. And Nitro will not cover because I am not original owner

This may be a dumb question, but how did you notice the blisters? were they evident even while on the trailer?

[8man]

This may be a dumb question, but how did you notice the blisters? were they evident even while on the trailer?

No the fiberglass guy was looking at some cracks under transom. Said we need to get it up off trailer to look under it and I said ok. So that is how he found it

[lpugh]

Go to this link and open all the sub links there and do some research there, it will explain a lot of things, then give mark a call with the required info and I am sure he will fix you up
http://www.bbcboards.net/showthread.php?t=172588