343 has the Kiwi Prop and so far (after 1 year) I love it! First of all, it was only $1300 or so plus installation
(which we got for free because the dealer was doing a lot of work on the boat out of the water
Here is where we have benefited:
1) Much better performance under sail...we can actually sail in sub 8 knot
winds. With the old 3 blade fixed, we just couldn't get much movement because we were towing a big bucket
2) Better manners under reverse. With the old 3 blade, reversing was a circus. It would go from not catching for what seemed like minutes (as we drifted into danger) to suddenly catching and shooting the stern to port with prop walk and the bow to starboard. Now, its a gentle momentary drift to port and then it catches firm.
3) Hidden benefit...I have better galvanic protection. With the stock Beneteau
fixed prop, the zinc went on the prop nut. It was a tiny little cone zinc that I was lucky to get maybe 8 weeks out of since it was right in the way of the prop turbulence and would wear down very quickly. Very poor design Now, with the Kiwi, I use a much larger collar zinc right on the prop shaft itself...and I'm getting much better wear out of the zinc as well since its no longer being shorn off by the prop turbulence. True, I could have used a collar zinc before as well, but it just didn't feet with enough clearance to get water
flow to the shaft seal
4) I haven't used this feature yet, but I may have to in the future. The prop is designed to "lose blades" in case of impact. Much like the design of a IndY Race
Car, in case of impact, propeller
arms will shear right off, dissipating the energy of impact and saving the hub and hopefully the shaft. Replacement prop arms are $110 each and can be bolted on with an allen wrench.
5) Prop pitch can be adjusted by yourself with a 4mm allen wrench. Mine was tuned too weakly, so I pitched it a bit to get back some of my performance under motor
In terms of negatives:
1) The feathering prop does free wheel
while under sail since Yanmar
now recommends keeping the transmission
in neutral while sailing. It has an audible low frequency hum that could be mitigated with a shaft lock...thats extra expense. I've heard some feathering props autolock
2) I've lost
3/4 - 1 knot
in performance under power...especially prevalent in situations when I'm fighting the river current
doing bridge work to get home. 2800 RPM
used to be 6-6.5 knots with the fixed prop...now 5.5-5.7 knots if I'm lucky. Part of this may be that the prop isn't pitched just right yet, but I'm hesitant to take it TOO far off spec thats recommended for my boat.
3) It needs to be lubed/greased at every haulout. I haven't had my first haulout since putting in the prop yet, but I'm not looking forward to this task
All in all, one of the BEST upgrades I've had done to our boat was adding the Kiwi Prop.