re propped Cutwater 24C like a new boat

Edmund

Well-known member
Joined
Aug 8, 2021
Messages
55
Fluid Motion Model
C-32 C
Replaced the Yamaha SWS 16 P prop with a 4 blade 15P prop....and it improved performance all across the range....low end, mid range, and top speed.

I highly recommend this to all 24C owners....the boats happy RPM seems to be 5200...it's high up on the steps, riding light, level and about 39-40.
 
Could you give more information like manufacture, prop dimensions, part number,fuel economy and do you have a 250 or 300 hp Yamaha. And WOT if possible. Thanks
KKRCRACE
 
It's a Powertech OFS 4 - I worked with Ken at Propgods.com and we tried a 16P four blade and that was not satisfactory, so he shipped me a 15P 4 blade and it was better than expected. It was the rare trifecta of better low end, mid range and top end speed improvement. I was willing to lose a smidge at the top end to get the other advantages, but it was a bit better there too.

And of course, being a four blade, you have a bit more response around the dock - and our lift is in a tough wind./current environment .. and with the transom design, the C24 is lousy in reverse....it still is but the fourth blade helps for sure.

Depending on conditions, some typical numbers - that I've recorded on my iPhone cam while operating...played with the engine trim a bit...did not use my tabs, which are so small they are virtually useless, for these tests.

37 at 4800 with 1.9 fuel
44 at 5700-5800 with 1.2 fuel...touched 45 very briefly and would drop to 43 some but 44 held pretty good.
39-40 at 5100-5200 with 1.9 fuel.....seriously seems like 5200 is the happy spot. Twin step boats are known to be more efficient at the higher cruise ranges.....and this would fit that.

I don't think 45 is the true top end in still water....I almost never have still waters or still winds....but it's a true 43 mph boat for sure.

250 Yamaha engine. And I cannot recommend Ken at Propgods highly enough. Dude started giving prop advice on some websites and it turned into a career and business for him.

And Cut should put this prop on their 24s......standard. It's simply a better boat with it.
 
Edmund, to get the most efficiency with your new prop does your motor like to be trimmed up some and roughly how much?
With my C24 and 300 Yamaha with factory 3 blade it is most efficient trimmed to about 21 on my Garmin which is 3 bars on Yamaha display. I ordered a 4 blade from Ken and he is sending me one with 16 pitch because I have the 300. Thanks for the info.
KKRCRACE
 
Yes, likes trim...and I do not have a trim indicator...but I'd say more like 4-5-6 on a typical Yammy display. (I have a Robalo 206 Cayman with Yam 150 and Yammy display...so this is pretty good guesstimate.) For me the sweet spot is 51-5200 rpm and a speed of 39 give or take...and the fuel reads 1.4 to 1.9 in that range, which is about what it reads at 4400-4800. I think the boat's happiest RPM is 5100 or so....and that was actually true with the 3 blade. Also, at the higher RPM and trim, the boat does not list - which it does for no reason at other speeds. Very interested in your results...I think you're gonna want the 15P....ultimately....but I may be wrong. Send me results too...thanks.
 
Edmund, thanks very much for all the info. I sent you a PM earlier today after seeing your comment in the Sharrow thread. But you gave me A's to all the Q's in my PM here, so no need to reply unless you have more to share. (And tho' I didn't mention it in the PM, my C248 also has inexplicable lists at times - glad you mentioned that). No surprise that Ken (KKRCRACE) jumped on this; he doesn't seem to miss much. And Ken, no Yamaha approved chip upgrade for the 250 to a 300. Oh, well....I'll spend the $$ on a prop instead. 😉

Ken Reeves, owner
propgods.com
kr@propgods.com
(941) 735-5808
 
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