Fitted a Kiwi prop 2 weeks ago have since done approximately 300nm motoring, motor-sailing and sailing. Early stages but are most impressed so far. My main concern was i would lose thrust motoring to wind this has definitely not been the case. Crossing wide Bay Bar ( Qld east coat of Australia ) which all up is approx 7 nm by the time your fully clear we were pushing 3-4 knot current and still maintaining 3+ knots while passing other boats at cruising Rpm. It is obviously a better match for my 3GM30 Yanmar than my previous 3 blade fixed prop resulting in more power and very efficiently fuel burning ( cleaner transom ). Heading sth down the Qld Australian coast means going to wind. Motor sailing with the new prop is definitely improved. The 2 days that we sailed we had the wind just forward of the beam most of the time sitting somewhere between a beam reach and a close reach the apparent wind speed approx 12-14 knots with a 1.7m swell, at this angle, wind speed and swell we averaged 6.1 knots over approx 10 hour period each day. Keep in mind this a 32 foot boat with a spec waterline of 25.5 feet. The bottom had fresh antifoul which would obviously would be helping. We are a fully loaded small cruising boat and are quite happy with this sort of performance. Hard to say because no two sailing conditions are the same but I believe I’ve picked up 1/2 to 1 knot sailing in these conditions. More thrust in reverse at low rpm. Haven’t sailed down wind yet or in very light breezes, looking forward to see how it goes. Reasons for choosing Kiwi prop were
a/ price $1500 cheaper than autostream ( martec )
b/ weight of prop
c/ sacrificial nature of blades
d/ low maintance
e/ independent feathering blades
Cheers Dale Tournier
Freeform.
Hi Dale,
I am delighted to hear you are happy with your Kiwiprop. We fitted one about 18 months ago and have had much improved sailing performance, similar to that which you report. We did lose some motoring performance, our old 3 blade was very well set up for the engine, and we had a big loss of power astern. The latter is explained because the KP goes to maximum pitch in astern and as our reduction astern is very close to the reduction in ahead, the prop becomes way over pitched. On the Yanmar gearbox there is a much bigger reduction in astern than ahead and the increased pitch of the KP astern compensates very nicely and would be a big improvement on a conventional prop.
We have had one or two technical problems, possibly due to the fact that our installation is near maximium capability for the KP, but the after sales service has been exceptional and I feel we have been very well looked after. Our current problem is we have no astern. The conical bearings that hold the pitch for astern operation have sheared off one by one during the week. I think this is due to metal fatigue and the fact that these bearings will be subject to greater loads because of our lower reduction ratio astern. I will order replacements next week and plan on replacing them each year as routine maintenance. I also carry a spare set of blades.
Best wishes for Xmas,
Hi all,
I spoke to John at Kiwiprop about the failed conical bearings and he immediately sent me 3 replacements with heavier 8mm screws which should fix the problem for good. The old screws were 6.0mm. In addition he sent me three spares as I had said I would look at replacing these items from time to time as preventive maintenance. He did, however, decline to send a bill even though I felt we were getting into the area of wear and tear rather than warranty. As I have said before, I couldn’t be happier with the after sales service, it really is exceptional, especially when you consider that I bought my prop second hand!
Best wishes for Xmas and the New year. I do hope you guys in Europe will get a little of that Global warming soon! 