Propellors

[mmts]

Probably an old topic, but wondering whether to change my existing propeller back to a two blade. The current 3 blade I think is a bit over pitched for my engine. What do most people run.......blades, diameter, pitch ?

[storm petrel]

I run a bronze 15" two blade prop. Seems about right for my 14Hp Yanmar. I would like a folding prop but as I do not race I could not justify the expense for the small gain in speed.

Cheers,
Mark (II)
Storm Petrel

[fullandby]

I have a 3 blade prop, unsure about the pitch and diameter driven by a Yanmar 20hp. Mine is a bit overpitched as well, I get black smoke at about 3000 rpm and 6 knots. I think the pitch was optimised to run the motor at about 2600 revs and 5.5 knots which is economical on fuel. Being limited to 3000 rpm doesnt allow the engine to develop its full power but it seems to be a reasonable compromise.
The drag from the prop doesnt seem to be a significant problem, I can still get 5-6 knots in a good breeze. My prop is in front of the rudder so I dont have the option of a folding prop even if I wanted one.

Cheers,

Bart

[Phillip]

Morning All,
I also have a 3 bladed 13" prop. With my 10hp Nanni I can get hull speed of just over 6knts without any problems.

That is except when I haven't been over and cleaned it will be using propspeed when I next come out for a scrub!

Phillip
SEAKA