Spare Prop

[Hunter]

Currently running a Honda SS 3 X 14 1/4 X 17R on my 220OP / HT / ET with a 2017 Honda BF250. Really pleased with the low end TQ. At WOT on clean flat water with a medium loaded boat, 3/4 tank, 2 adults and 2 big dogs, I'm hitting 6200 rpm (top of my max RPM range) and 43 mph.

But......I just realized after having this boat for all this time that I have never got around to getting a spare prop...... Got so used to always having the spare on all previous boats that it's just something that is so automatic that I just completely spaced it..

SO.....moving forward, need to remedy that brain fart asap.   I could just get another SS or AL 14 1/4 X 17 and know exactly what I was getting.... or .......something else...

My thinking is to go up to a 19 pitch which might drop the RPMs to 5900 or 6000 but maybe give me the same top end speed.   Also. I completely get how pitch affects performance / rpm's etc.   Go up in pitch and it will lower the rpms at WOT.   What I don't totally get is how prop diameter plays into everything..

Any suggestions or opinions are appreciated?

PS..... Yes I already am fully aware of the advise to find a dealer or service that will let me test drive different props so..... I will look into that also.

Thanks..

[Fisherdv]

The larger prop diameter lowers RPM, the smaller diameter raises RPM,  (Less surface area and drag to turn). How much RPMS are affected will depend on the diameter change, but usually +/- 200 RPM.

[davidsea]

   Hunter:  Your numbers sound pretty good as-is.  A 2" bump in pitch would likely be more than you want, but an 18" pitch will not be very common.  Bear in mind that a diameter change has about TWICE the effect as a pitch change.  ( 1" diameter change = 2" pitch change)   Try a Solas Amita aluminum 4-blade.  Cheap enough ($114) that it's a great spare even if it's not the perfect solution.  The Solas 14.5 X 17 4-blade, adds 1/4" in pitch and a fourth blade, which should bring you down a couple hundred RPM.

[Hunter]

Thanks for the responses guys.... sincerely appreciated. 

Thanks!.....  so if I am understanding correctly,  it sounds like if I go down to a 13 diameter and then up to 19 pitch..... my max rpms won't change much and I will lose low end grunt but gain some top end speed.   

All in all.... I really do feel that I am currently propped correctly.   I just want the redundancy, safety and common sense of having a spare prop onboard.   

I really don't have any current plans on whacking my prop, but sh&t happens..   I might just go with an aluminum equivalent of exactly what I have now and call it good...   Do you think that is a decent and safe option?   

[Danno]

If you go with the 14 1/4 X 19R, you'll run quieter at the same speeds you run now because of the lower RPM's.

[davidsea]

  Sorry, meant the 14.5X17-4  adds 1/4" in DIAMETER, not pitch, and with the extra blade area, should drop you 200RPM or so. Adding 2" in pitch and staying with a 3-blade (14X19-3) doesn't seem like the way to go with a big, heavy boat. Overpropping to keep RPM down just lugs the motor - better to prop it right and reduce RPM with the throttle.

[Hunter]

Thanks for the responses....all great information to consider.   I did find a good prop calculator tool on the Honda site,, (see link below) .   You just enter your available info and it suggests its "opinion" of your best prop option.     When I entered my current hull info and performance data, the calculator came back suggesting either a Solace Titan HR3 3 X 15 X 19  or  Solace Lexor 3 x 15 1/4 X 19. 

https://marine.honda.com/parts/propeller-calculator

[Scottjohnson59]

So do you carry a spare prop on the water? could you change it out there? Or do you carry it in your truck and change it on dry land when you get back? The reason I ask is, it seems to me there is no way I could change a prop on the water. I can get pretty much any prop on the market delivered or at a store Mon-Sat. It took the good folks at Tacoma propeller two days to turn around an Aluminum prop that needed welded. So save the bucks be careful and you may never need that spare prop.... MTCW>>>>

[Hunter]

I guess it just the boy scout in me that wants the option of a spare prop.    You never know what  can happen and even with perfect navigation.... there's still submerged deadheads and other lurking prop killers out there.   

Just think if you've just planned and spent a boatload of dough to go up to Nootka for a week and you whack your prop on day one...... good luck getting Amazon to deliver one.   

If 30 miles out in the blue on a tuna run....then yes, it would be difficult without an inflatable to change out the prop on the water.   But if your inshore, then you can go to a dock or to shore with the kicker and do it..   

Also, I have the Buddy Anchor system so once I have it set up I can literally have the boat set bow out and then pull the stern into 6 inches depth and easily change out a prop.

Now you have even thinking about keeping a cheap 2 man vinyl inflatable on board just in case I ever needed to change a prop out in the blue..

http://www.arimaowners.com/index.php?topic=14107.msg164672#msg164672

[Markshoreline]

I have backed up to an island in the S J's to change a prop- not a big deal.  The spare prop doesn't have to be perfect pitch, just enough to get you home.  Just make sure it fits your outboard.