KiwiProp North American agent here. Some good feedback on this thread, but thought I would offer some possible clarification.
IF your new KiwiProp is stalling your engine
right from the start, you have to recognize the difference between a symptom and a problem. We very specifically set the props up based on the HP, max rpm
and reduction ratio of your boat. As someone mentioned, we are very diligent about confirming and cross checking that information to make sure it makes sense. IF you tell us your 20 year old diesel
has 50hp but it is only putting out 40hp because of a faulty injector, carboned up exhaust
, clogged fuel
filters, etc. etc. then it will likely motor
in forward fine but not reach max rpm
as it is supposed to. In reverse, it might stall.
You could decide to treat the symptom and put your old fixed prop on that didn't give you any reverse thrust and might have been underpropped since day one, or you can treat the problem and have your engine
There are some inexpensive work arounds to keep the Kiwiprop on and treat the symptom and defer more expensive options like rebuilds or repowering, but keep in mind the KiwiProp is just exposing the problem, not creating it.
IF after a year or two of use you start to experience stalling in reverse that is absolutely a completely separate maintenance
issue, and you need to get grease into the hub and work it back and forth until you are sure it is not binding anywhere, then put some more grease in just to be sure!
There are now thousands of KiwiProps out there for over 15 years. Virtually all of them are being installed and maintained by the owners since we sell primarily direct from the factory. A small percentage have reversing issues that are almost always related to a lack of regular greasing. The prop will actually give you some warning before you have a major problem- an initial puff of black smoke when backing up. its not hard to grease, even underwater, and we ship a grease fitting with every prop.