KiwiProp - revs astern with VP 2020 engine?

[Plevier]

I have a KiwiProp with a Volvo Penta MD2020D with MS10L gearbox.
The engine is supposed to rev up to 3600rpm max and I have set the forward blade pitch to get near to this (about 20 degrees).
Going astern the KiwiProp blade pitch is non-adjustable at 23 degrees. The engine will only go to 2000rpm or just over with wide open throttle and I don't think it feels very happy. Initial bite when you go astern is good but sustained power delivery is limited. (I have quite a long reverse from my mooring along a narrow channel.)
Can anybody else with the same set up comment please, what revs do you get?
The Kiwi agent says it should be OK but I don't like it.
I'm considering attaching some packing pieces to the blade roots to reduce the pitch - anyone tried that? Alternatively if you have a machine shop you could make bigger diameter reverse pitch stops.

 

[AHoy2]

I have the same set-up on my SO32.2 and find astern rev limits similar to yours. Astern propulsion and control is ok at lower revs with no concerns about over-propping stress for the limited durations involved. The high pitch can result in rather faster astern speeds than desired and I normally drop in/out of gear mobo style as soon as moving.

As supplied the prop gave maximum ahead revs of 2,800. I adjusted this for max revs of 3,400 and the engine is significantly better matched at all speeds. I did spend some time carefully equalising the pitch setting across blades and have obtained smoother running.

 

[ianj99]

I have a KiwiProp with a Volvo Penta MD2020D with MS10L gearbox.
The engine is supposed to rev up to 3600rpm max and I have set the forward blade pitch to get near to this (about 20 degrees).
Going astern the KiwiProp blade pitch is non-adjustable at 23 degrees. The engine will only go to 2000rpm or just over with wide open throttle and I don't think it feels very happy. Initial bite when you go astern is good but sustained power delivery is limited. (I have quite a long reverse from my mooring along a narrow channel.)
Can anybody else with the same set up comment please, what revs do you get?
The Kiwi agent says it should be OK but I don't like it.
I'm considering attaching some packing pieces to the blade roots to reduce the pitch - anyone tried that? Alternatively if you have a machine shop you could make bigger diameter reverse pitch stops.

I too have a Kiwi prop and my 4108 won't do more than 1500rpm astern. This is not an issue because it bites very well, and 1500rpm would equal about 6knots so I can't see me ever needing to go flat out astern. I prefer the bite - 10tons of steel ketch needs it.

The downside is lots of prop walk to port and the need to 'coast' when needing to go slow!

However I may need to adjust the ahead pitch a little - max rpm is currently 2200. However this gives hull speed of about 6.8-7knots and a quiet cruising speed of 6knots at 2000rpm so I might leave well alone.

(In other words, there is no point in adjusting the pitch for max bhp rpm if your boat does not need this to reach its hull speed.)