test propeller

[99yam40]

that is a strange looking test prop, I would not have thought that was what they looked like.
looks something like an impeller from centrifugal pump maybe

[rodbolt17]

mine looks slightly different.
the EX snout is shorter.
as you increase HP it will blow throgh the test wheel.
this will lead to over speeding.
years ago Suzuki and mercury had a chart on how to cut down stock AL props to use as test wheels.
my copy was lost in the flood a few years back.

[Searider]

years ago Suzuki and mercury had a chart on how to cut down stock AL props to use as test wheels.
.

Got an old 21 pitch alu prop and want to machine it down as well - just to try how it will work .
Looking at the test props on the pics I think there will be not much left from the blades after machining ..