Best Prop. for a 9.9 Johnson for a Sailboat?

[jbsails]

I am about to mount my 1998 Johnson XLS on my sailboat tomorrow. I was wondering if there is a prop pitch that is considered to be the most efficient for the Sailboat application? Any thoughts or ideas would be most appreciated.

 

[boobie]

Re: Best Prop. for a 9.9 Johnson for a Sailboat?

The best way to figure out what prop you need for any boat is to have a tachometer, know the rpm range the mtr the runs the best in and test it with different props. Best to prop out at the top of the range.

 

[rodbolt]

Re: Best Prop. for a 9.9 Johnson for a Sailboat?

what Boobie said.

 

[dazk14]

Re: Best Prop. for a 9.9 Johnson for a Sailboat?

what Boobie said.

+2

Short of that... Many Sailors have used this prop and been satisfied with sailboats up to around 26'.

http://boatpropellers.iboats.com/Ev.../6159/?**********=755998827&*******=198974690

This topic has been debated countless number of times and there is no clear winner as technically, a 5" pitch would generally provide more conventional rpm numbers, but many Sailors dislike hearing the motor revving so high and prefer the lower rpms of the 7". Stick with a 4 blade prop.

 

[rodbolt]

Re: Best Prop. for a 9.9 Johnson for a Sailboat?

and I simply dont like hearing blowboaters whine.
there IS a clear answer and several of us typed it.
what blowboaters do after that isnt our issue.
that engine MUST be able to turn in its max RPM band or the engine is lugging at ALL engine speeds or its overspeeding and less efficient at ALL engine speeds.
last I looked sail boats have been made in 10 inch models all the way up to some 300+ foot models over the past few years.
blowboats are displacement type hulls, they rarely plane.
means the prop blade desighn and gearcase design as well as gear rtio is different on dedicated pusher(kicker) type motors.
its also why most dedicated pusher engines use the dual thrust blade design, gives about as much thrust fwd as aft.

 

[samo_ott]

Re: Best Prop. for a 9.9 Johnson for a Sailboat?

and I simply dont like hearing blowboaters whine.

Uh, did I miss something? I didn't see any whining?

The question that should be asked is what type of sailboat and how heavy? Maybe it's going on a modified laser and he needs a high pitch prop to plane, or maybe it's going on a 32'er 9000#er and needs a low pitch prop.

 

[jbsails]

Re: Best Prop. for a 9.9 Johnson for a Sailboat?

Ok...I suppose I left out some critical information. This is my first sailboat with an outboard...so a bit out of the comfort zone. It is a 25' sailboat.

So...it seems from above that I should consider a 4 blade prop...now I am not trying to go racecar or anything...I am only attempting to understand if there is an efficiency to a specific prop size/blade configuration for sailboats.

I am a powerboater as well as a "blowboater" so I don't have a dog in that fight...just trying to learn from those more experienced....

 

[samo_ott]

Re: Best Prop. for a 9.9 Johnson for a Sailboat?

Well I used to have a 24' Seafarer (sailboat), about 3500-4000#'s I believe. We had an electric start longshaft Evinrude 9.9hp on it and it was plenty. It had the base prop as far as I recall. If you had to reverse in a hurry trying to the dock it took awhile! It was like try to stop a supertanker. A 4 blade prop would probably made a tad of difference but probably not a lot. what you need is a larger diameter prop which you cant get on a 9.9.

Attached is a pic of the boat and the engine leaning against the tree, it's the best photo I can find. It's from 2002.