Not the right prop

[Guus]

Originally Posted by Cheechako

an INCREASE in pitch made it punch thru chop better? as well as lower HP at lower RPM?

Increase of the pitch will increase the water displacement of the prop . More power must be delivered. The RPM needs te be increased to free that power.At 2500 RPM the Yanmar engine will produce 8,5 HP. When we need more power (strong wind, waves) we open the throttle. Then the engine starts smoking. Decreasing the pitch will lead to less displacement and a lower power demand. We expect that we can increase the RPM as result that The engine will produce more power..

[01kiwijohn]

Y'know, Guus, you might want to do what I did.
I had lots of confusing advice when considering a feathering prop. Finally, I found a company called "Kiwiprop", in New Zealand (where else, with a name like that!).
John Blundell, the proprietor, gave me a list of boat parameters, and instructed me on the specific information he needed. They then sold me a prop, sized and pitched accordingly. The price was also very competitive, delivered to my door, in the USA.
These props are stainless, with replaceable plastic blades. The mechanism is quite simple, so you can service it yourself, at haul-out. You can perform any required pitch adjustments, after re-launching the boat, in the water with just a small allen wrench. (I stuck the wrench into the end of a piece of wood dowel, so the diver wouldn't lose it.)
I have put over 1600 engine hours on the boat, since installing that prop, and it has performed flawlessly. As it goes into "full pitch" astern, it will exacerbate any sideways a'pull' when starting out, but that has not been a significant problem.
At each haul-out, I dismantle, clean, inspect, lube and reinstall it, using basic hand tools.
After six years, I couldn't be happier. I am sure Mr Blundell could help you too.