Z8 top speed

[2boatjoe]

I have a 2011 Z8 have only had it for a couple of months when I first got it I took it out with a buddy of mine and no gear 1/2 tank of gas and saw 69 think it would have gone a little more but chin walk kept me from trying. Took the boat out last two weeks on a trip to florida and when it had 3/4 tank gas 2 guys about the same weight and gear and both live wells full the best I saw was 53. boat has a 250 Optimax same year as boat. I had it at the shop for a once over and they did plugs impeller and oil pump. That was all done after my first run but before florida. RPM's at 53 mph where about 5200. I am running a furry 26p i would give it a 5 out of 10 but again that was not changed.

thanks for any input.
Joe

[B.Combs]

I may be mistaken, but pretty sure you should be turning around 5600-5800 rpms at WOT. I have a Z20, and that’s what I’m turning. Also have a Merc 250.

[ZRT600]

Call your dealer and check your engine serial number for the compressor recall. Also what's your jack plate set up?

I'm running 66-70 with my Z9 with the same kinda load. I've seen 74.6 with a light load... 1 time thing tho lol. You should be running at least what I am with the same motor.

[bkeenom]

Make sure all of your plug wires are plugged in

[Lkmbjb502]

I have a 2011 Z8 with 225ProXS+25 Fury fixed jack plate which I have never moved - and light load I see 69.2-69.5s @ 5800-5900 - but really loaded with both consoles, 2 or 3 people and gear I loose 6 or 7 MPH at least and some RPM. My boat is seems very sensitive to weight and over-trimming - with a normal load (early or late in the year when the boat doesn't have half of BPS in it) - it runs 67-68 and never walks a bit - if light it starts to want to walk at the top but a bump of the trim down and it's fine.

If you are running a hot-foot - also might want to check and make sure it it moving full travel and isnt binding somewhere. Another thing that may or may not be an issue but something to check is your alternator belt - as I have gone through a few in the last 500 hours with mine (supposedly need to be changed every 100 or so hours I had one blow up at about 250 hrs and changed another one at about 380hrs) - and at least in my situation when they got old and started to slip a bit - I got some low voltage alarms even when running - by moving the trim - and I have been told by Dealer and others that lower voltage could impact performance to some degree (but not as much as you are experiencing).

Good Luck.

-Jonathan

[BMCD]

If its running a little ruff at idle could be a coil. Need to verify ur getting full throttle.

[2boatjoe]

Right now it is at the shop I will update when I get it back.

[2boatjoe]

Well I got it back from the shop. Motor checks out. They checked for WOT all good. No recalls on motor. I guess I have a larger load than I thought. I did check the hull it is good and flat no hook. I think I am going to get a new prop mine is a little beat up.

[rlkingsbury]

I had an 09 Z8 with 250 XS, dual council and it would run 77 GPS by myself. 25 Fury prop, 10" jackplate. Best I saw was 78. Would run 75 all day long. Very quick boat. Much faster than my Z20. Your RPMs are way to low. Should be 6000 rpm. Sounds like you have too much prop.

[zeke4351]

I had an 09 Z8 with 250 XS, dual council and it would run 77 GPS by myself. 25 Fury prop, 10" jackplate. Best I saw was 78. Would run 75 all day long. Very quick boat. Much faster than my Z20. Your RPMs are way to low. Should be 6000 rpm. Sounds like you have too much prop.

+2 on too much prop