Z7 WOT RPM's correct?

[Mike Wagner]

I just completed the break in for my 150 Pro XS "by the book", and trimmed it up for the first time. At WOT, and trimmed to 1/2 on the trim gauge, my GPS speed ranged from 58 to 60, and my RPM's were 5200-5300.



My question is- 5250 is the low end of recommended WOT RPM's according to the book. Am I ok where I am, or should they be higher? I know that "lugging" is not good for the motors. FYI, I am running a Tempest 24 plus and have a total of 5 hours on the motor.



Thanks,



Mike

 

[Bob Bourget2]

I would like to see a couple hundred more.......perhaps a 23" Tempest.....

 

[Mike Wagner]

Thanks, Bob.



I'm wondering why they rig these Z7's with Tempest 24's from the factory if that puts you at the low end of recommended RPM's. I know I've read that these motors can "loosen up" after 10 hours or so and start to rev more. Is there any truth to that, or can I expect it to stay 5200-5300 if that is what I see now?



Mike

 

[Bob Bourget2]

Yes it's true they loosen up some, but not to the threshold we would like to see. Too many variables that affect wot rpm to really nail down the right prop. The factory does a really good job of getting it in the ballpark. Production tolerances, load, weather, water conditions, and altitude play an important role in choosing a wheel. Now that you have a good baseline, you can either have your prop "worked", or, get another that puts you closer to the sweet spot. You should have a spare anyways....

 

[Mike Wagner]

Bob, thanks for the great advice, as always.



Mike