In case people are interested Z21 with 300XS

[Zimmer]

I've seen some people wonder what a Z21 and 300XS would do. Finished initial break in and motor now has 6 hours on it. Have down some test runs now at WOT but for no longer that 30 seconds

26 Tempest was turning just under 6100 and getting 75.2mph. Boat was "galloping" a lot and I need more seat time. Have not played with jackplate height much or weight distribution. I'm interested to try a 27 Tempest and especially if I can get my 26 worked by Croxten.

Ran a Fury 26 and it would run. Would only spin 5500 and didn't break 70. I think that prop is bunk.

[texasfisher]

Hi Zimmer. I also have a Z21 with 300XS. It came with 24p Fury 3 blade. Got a little 5 hours on the motor. Wide open I've seen close to 75, actually about 74.9 at about 5850 rpm. That seems to be the rpm limit for now. Maybe later the motor will loosen up and I will see 6100 like you get. Really like the motor on the Z21. I noticed you used the word "galloping". That's a good word for what mine does also at top speed. Its not chine walking but the front of the boat does bob up and down. Maybe more seat time and trimming practice will take the galloping out.

[BigBadBass]

Did ya try the fury 24p? I’ve heard that the prop w the 300xs...it is for my Verado 300.... 75 is great! Fastest I got was 77 but unrealistic load....full load at least 72mph - 74mph consistently full gas, wells and 2-3 ppl... mine is definitely a chine at top speed... have to really drive it... never tried to top that yet but I will later on haha. Manual jack 8”. Really want to try a 4 blade. Heard it’s great to drive in w little sacrifice in top end

[berudd]

At risk of sounding like Captain Obvious here, if the boat is porpoising then it sounds like your trimmed to high. I'd try to pump it down a notch, or raise the motor a bit, and see if it stablilizes. Might even pick you a little on MPH since every time it comes down the extra drag is going to slow you down.

[TRCM]

A fury prop will run a lower rpm than the same pitch tempest as it is made from a stiffer material.

If you ran 5500 with a 26 fury, and 6100 with a 26 tempest, you need to just the prop-pad height for each prop.....they will run best at different heights. The rpm difference shouldn't be that high, maybe 300 or so at best.

You need to do some tuning with what you have, and learn to keep the boat from 'galloping'.....not only does it kill speed, it is unsafe.