No.of blades on a prop?Reason

[Mike Redmond]

Something surprised me about props,yesterday.I have a1981 9.9evinrude,and a2008 8hp yamaha and they both have 3 blades on their props.I am now looking at a1978 9.8hp with 2 blades on its prop, its a motor thats reasonably close in hp than the other ones that I have,,whats the diff in performance with 2 or 3 blades...just confused? A simple ans.could clarify my dilemna? Thanks Mike

 

[smokeonthewater]

Re: No.of blades on a prop?Reason

generally fewer blades = more speed/ efficiency
and more blades = smoother/better holeshot and pulling power

 

[Texasmark]

Re: No.of blades on a prop?Reason

Additionally, some will have normal thrust props, and others will have the ears bent back in weedless form in both 2 and 3 blade versions. Years ago, I read where the weedless version cost you some thrust, but you accepted that to get the weedless performance.

I used to do a lot of fooling with props on smaller engines when I was starting out, but I couldn't find that much difference between types and pitches other than on one occasion, going from a 2 to 3 blade standard prop I did notice a better hole shot......yeah ha ha hole shot with a 7.5 hp. Boats didn't go that fast to start with and I had no instrumentation, even a speedometer.

Mark