Extendo Prop by Performance Propellers

[aquavitae]

Has anyone tried a Urethane Extendo 2 blade fixed prop ?
I have a 1982 sea runner trimaran 37 ft , with 27 hp Yanmar engine. It spins a 13 inch prop on a 1 inch shaft (2.62 ratio) and I can only get 4.5 to 5 knots out of her. Prop is bronze, 3 blade, fixed. I am told the problem is the prop size.
I bought a 16 x12 two bladed Extendo prop that will ( hopefully) fit on the existing shaft and still give enough clearance from the hull by extending the prop 6 inches further aft. Prop is made of urethane and looks pretty stout. Manufactured by Performance Propellers of Homer, NY

Any experience and feedback with this prop- good, bad or indifferent is greatly appreciated

Bob Petersen
St Thomas

[atoll]

would think your original prop is way too small for that hp and ratio,thats about the size for a 3 ton 25 footer.

might want to do some sum's try
Vicprop - Propeller Calculator

[Rakuflames]

Originally Posted by aquavitae

Has anyone tried a Urethane Extendo 2 blade fixed prop ?
I have a 1982 sea runner trimaran 37 ft , with 27 hp Yanmar engine. It spins a 13 inch prop on a 1 inch shaft (2.62 ratio) and I can only get 4.5 to 5 knots out of her. Prop is bronze, 3 blade, fixed. I am told the problem is the prop size.
I bought a 16 x12 two bladed Extendo prop that will ( hopefully) fit on the existing shaft and still give enough clearance from the hull by extending the prop 6 inches further aft. Prop is made of urethane and looks pretty stout. Manufactured by Performance Propellers of Homer, NY

Any experience and feedback with this prop- good, bad or indifferent is greatly appreciated

Bob Petersen
St Thomas

I put one on my boat last fall. It doesn't seem to grow sea critters quickly, and it seems to have a lot of power: I only have a 20 hp engine (new), and if there's no current or wind on my nose, my boat moves at 6.5 KNOTS (not mph) -- and that's not at redline. Redline on my engine is 3600 and I have gotten up to 6.5 at 3200.

Someone suggested to me that it might be more likely to break if it hit some obstacle in the water. That may be true, but the company replaces the propeller in that case AND you can limp back into a port with one blade safely because it's so lightweight.

They claimed improved steering performance in reverse but I haven't noticed that particularly.

I'm very happy with it.