Prop recommendation 17' Bowrider + 140HP Evinrude

monnewbie3

Petty Officer 3rd Class
Joined
Sep 12, 2011
Messages
90
Hey Everyone,

I'm looking for a prop recommendation for a 17' Starcraft Tri-Hull Bowrider with a 1978 Evinrude 140HP(140843C).
Currently, there is the stock prop which is pretty banged up, it's an Aluminum 3 blade (not sure of the pitch).

I like to do lots of watersports, fishing, and trolling, so most of my activities are in the mid RPM ranges.
At WOT the boat does about 40MPH (with only me in it, 36ish with 3 people, GPS and speedo confirmed) trimmed out to about 5400-5600RPM.

I've been looking a lot at the Solas Rubex 4 blades.

Any advice on what prop I should go with would be great!

Thanks in advance,
 

louiefl

Petty Officer 2nd Class
Joined
Apr 11, 2012
Messages
119
Re: Prop recommendation 17' Bowrider + 140HP Evinrude

You need to figure out what is on there currently. Pull the existing cotter pin, washer, and castellated nut, and then the prop should slide off the shaft. If it doesn't search for "stuck prop". There should be a pair of numbers visible once you remove the prop, mine shows 14x17 which means it is a 14" diameter x 17" pitch prop.

Seems like you are making it to the upper range of WOT, so if you are happy with performance, I'b be tempted to buy another 3-blade aluminum prop, and send yours out for refurb as a spare. new ones are around $100, refurbing is about half that. Aluminum is easy to repair and can take a beating.

If you want to improve your holeshot, drop down a pitch size; if you want to increase upper end, then increase the pitch.

Not sure why you are going to a 4-blade, but you do lose some hole shot over a 3-blade, so you would want to change pitch by an inch:

http://boatpropellers.iboats.com/propeller-tutorials/blades/?*******=420635208
 

monnewbie3

Petty Officer 3rd Class
Joined
Sep 12, 2011
Messages
90
Re: Prop recommendation 17' Bowrider + 140HP Evinrude

Hey there thanks for the reply.

I'll pull my prop and see if I can get the number off it.

As for the 4 blade prop;
I was thinking a better holeshot could be better for water sports as the boat would get on plane quicker and give a little more stern lift in the mid RPM range.

Cheers,
 

steelespike

Supreme Mariner
Joined
Apr 26, 2002
Messages
19,069
Re: Prop recommendation 17' Bowrider + 140HP Evinrude

louiefl, I think you misread the prop descriptions. A 4 blade will generally have better hole shot than a 3 blade.
Also When dropping down in pitch you should consider the present rpm. while it should help hole shot it may lower top speed
and could over rev.
You can increase speed by increasing pitch again it depends on the present performance.
 

monnewbie3

Petty Officer 3rd Class
Joined
Sep 12, 2011
Messages
90
Re: Prop recommendation 17' Bowrider + 140HP Evinrude

Hey steel thanks for the reply,

So the issue I may face is I may over rev the engine on a 4 blade since I'll be stepping Down the pitch?
I don't mind taking a small hit on top end, what would you recommend I do to keep it from over revving while still obtaining better hole shot and mid range power ?

Thanks
 
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