Mercury / tohatsu/mariner 20hp fourstroke

[sparky666]

If you have this engine and a light sib (honwave 3.8 or lighter) I have a new 9.25 x 11.5 prop for sale on eBay
I tried it on my honwave 4 and achieved 5500 rpm a fair bit away from the 6100 possible
Top speed reached 22 mph at 5500 with only me on board and a tank of fuel.
The original prop 9.25 x 10 reaches 6000rpm and 25 mph on a good day.
I think that a mercury mini rib or light sib could benefit

[Locozodiac]

If original delivered prop achieved near best top wot rpm, how did you managed to have 2 ? Bought a spare one to test. No prop pitch will give excat 100 + rpm. Usually 200-300+,-


Usually standard delivered medium pitch props on light applications delivers near full wot numbers as you have confirmed under trial with tach.

Happy Boating

[sparky666]

It was one of those things that I knew the answer to before I even tried it but it's the human condition I tried it anyway
I've never managed to change a prop yet and get the textbook 100rpm per inch , and I've wasted lots of money on props in the past and seen other people waste even more
Around 350 rpm per inch is very typical