40hp recommended size/pitch prop

[sharmac]

My husband just bought a 1995 40hp Force outboard - no owner's manual of course - and needs to replace the prop. What size/pitch prop is recommended for this outboard on a 16 foot Aluma Craft boat?

 

[b.gagnon]

Re: 40hp recommended size/pitch prop

What pitch is on it now? I would guess that you need somewhere around a 15 pitch, but it really is impossible to know without more info. <br />Some info we need is:<br />What is the max rpm @ wide open throttle, with the typical load that will be in the boat.<br />What kind of performance are you looking for, top end speed or hole shot?(You usually can’t have both)<br />Weight of the boat<br />Engine height. At what height is the anti-cavitation plate located above or below the bottom of the boat(Flat plate above the prop).<br />After you get as much info as you can, post it in the prop section.<br />Choosing the correct prop, to run in the proper rpm range can be a difficult task and is almost impossible to do without rpm readings. Even rpm readings from the original motor could help.

 

[roscoe]

Re: 40hp recommended size/pitch prop

And you thought this was going to be easy.<br /><br />With so many unknown variables, I would go with a 15pitch if the boat is an open light weight hull of 300-500 pounds.<br />Would go with a 13 pitch, or a 12 pitch, if the boat is heavier.<br /><br />This would be a starting point, and prop may need to be replaced with another if performance is not right.