What’s Your Sweet Spot?

Perfect run

What? Well, this past weekend while out on the boat, Jimmy was driving and man she was running smooth. Butta smooth, and we both said in unison, man she likes this RPM. And it dawned on me. A STORY! Hey its getting cold and story ideas are gold. And we have never touched on this subject. Does your boat have a sweet spot? Mine is around 1800 – 2200 RPM. She just runs smooth, and rides at a nice clip.

Around 2,000 rpm – Photo Scott Sawyer

I wonder if one of the engineers out there, knows why? Is it the engine size? Some engine innards? Prop? Maybe those nice Kocian Gauges? Here is An older video of WECATCHEM going full throttle. The speed is not all that different. Faster, but a lot of forced feel. She runs smooth, but her sweet spot is the 2K mark,

28 replies
  1. Bob B
    Bob B says:

    Our Deluxe 95HP original K just breezes along on a nice plane around 2300rpm with that glorious flat-head sound. 28000 is fast and I usually don’t bother going into the 3200+ range. 2300 all day long.

    (That’s wife’s hat brim; not my nose.)

  2. m-fine
    m-fine says:

    Squirt won’t even get on plane at 1800. She likes to run between 3000 and 4200. Above that and you get more noise and fuel burn for little gains in speed, below that and the jet is not very efficient. Anywhere within that range, the engine, drive, and hull seem equally happy but the optimum is selected based on water conditions and how much kidney shake and teeth rattle you are looking for.

    The Penn Yan has a few sweet spots depending on speed you want to go. The slow one around 1500 varies with weight on board and weight distribution. There truly is a sweet spot mixed amongst unpleasant spots at lower speeds on that boat with resonance in the prop/shaft/tunnel drive area. At higher speed cruise, the SBC V8 hums along at 3600. Above that, the gains in speed are minimal for the extra work and fuel.

  3. Bilge Rat
    Bilge Rat says:

    2700 RPM on a 25 foot Lyman with a Graymarine 327 V8. Everything just seems to be in harmony at that speed.

  4. Flash
    Flash says:

    Flash has a few, 2300 for a nice slow hanging out with the family kind of cruise, 2800 is a good pace that usually keeps ahead of all the woodies on a group cruise and out of their chop, and 3400 if the water is calm and I wanna stretch her legs for a longer cruise. Short bursts of WOT and 4000+ are always in the mix too. Hell, what am I saying, I’ll take any RPM, and they’re all pretty sweet.

    P.S. She’s still for sale.

  5. Troy in ANE
    Troy in ANE says:

    Sounds like we are going back to the days of “Edgy WoodyBoater” when we are asking about the SWEET SPOT!

    • m-fine
      m-fine says:

      We are talking about engine RPM, NOT the spots members of Congress and Hollywood types like to touch on their subordinates!

    • Dick Dow
      Dick Dow says:

      Hey Troy,

      I think we have a roll of that upholstery fabric we were going to get rid of… Need some? 🙂

      On another subject – all of my boats seem to be happy at around 2400 rpm, give or take a couple hundred depending on load and water conditions…

  6. Alex
    Alex says:

    Depends on the boat. ’59 Cavalier with the K, 2,200. 48′ Scripps Sportsman, 1,200. ’71 XK-18 jet boat with original 350, WOT, of course, about 4,200. While it lasted. ’70 XK-19 with newly rebuilt 427, probably about 3,000, but the magic happens when the secondaries open so who cares about a sweet spot. Ditto the ’68 20′ Grand Prix, also with a 427.

    All boats have one common sweet spot though. Even my 60 hp Whaler. It’s the sweet spot when they fire up and first idle. That’s when I realize I’m in my sweet spot too, just to be there.

  7. Dennis J Mykols
    Dennis J Mykols says:

    I agree with Alex, firing up that big block 454 in the Coronado is MY sweet spot, we cruise at 12 to 15 mph which is around 1500 1800 rpm, and that gives us a nice rumble out back, smooth ride in any wave condition, and slow enough for my boattress to sight see along the shoreline.
    In real rough whitecaps or boat waves, I find bumping her up to 2200 to 2400 rpms and setting the trim tabs down just a little, gets the hull up and over the rough stuff and a smooth ride at 22 to 25 mph.
    In my 1984 Whaler with a 90 hp 1984 Merc tower of power, MY sweet spot is wot. Love that old school screamin meemie sitting four feet behind me. unfortunately, that little 12 gallon gas tank will not allow me to do that for long…
    Damn, just writing about this makes me itchin to get back out there, which I will be next week, in Charleston, SC on my son’s Whaler and 70 degree weather.

  8. Ned Protexter
    Ned Protexter says:

    1963 Century Coronado with a 426 is 2100. Cruise all day at a decent speed without it being too loud to talk of you want but loud enough to say you didn’t hear them if you don’t like what people are saying.

  9. Sean
    Sean says:

    The 4.3 repower in Sea-J likes it around 3,200 for a decent cruise speed around 38mph. Pushing up to 4,600 results in 50mph +/- but, she’s “workin'” for it. On the dyno, the motor was run up to 5,300 but, I cant get her to turn that in the water….. so, I’m still looking for that perfect prop.

  10. Captain Nemo
    Captain Nemo says:

    Off topic. Has anyone had problems accessing the CCABC site? I renewed my membership and a while after that I was locked out of the member’s features of the site ie. The Boat Buzz, Photo gallery etc. The e-mails I send get bounced back as not valid address. Did they shut down?! Is there anyone I can contact?

  11. Matt
    Matt says:

    I have sent this to Troy. The ccabc is of course still strong. Clearly there is a glitch in the demons. We have this sort of thing happen with simple widget or code problems and the only way to find out is people asking. Thanks matt

    • Troy in ANE
      Troy in ANE says:

      Thanks all!

      We at the CCABC have migrated our site and Boat Buzz to a new server and are working through the glitches. I am working on an e-mail to inform all members about the process for resetting their password to Boat Buzz. We are Beta Testing it now with John in VA., Don Vogt, and our own BOD’s. The main site should be working fine and the e-mail system should be working.

      If you have trouble with e-mail try ccabctroy@gmail.com.


      Troy Hersom (AKA Troy in ANE)
      President CCABC

  12. Rich Marschner
    Rich Marschner says:

    Yep, I concur with many before me here; 1,800 to 2,000 is just right for my MBL, still powering Matt’s old barrel-back and running like a top.
    Hibernating for the winter up in Cayuga, NY.

  13. Flash
    Flash says:

    In regards to the CCABC site, we had to upgrade the software version on the Boat Buzz part of the site in order to keep up with the rest of the new website and migrate to a larger server. That is semi technical jargon for “It’s just something that had to be done.”

    Long story short is that the IT folks worked on it all weekend and into the early part of this week and it’s my understanding that they are finished with most of what needed to be done. Unfortunately, the current Users of the Boat Buzz forum will need to get a new password. Troy and his crack staff are working on the communication on how to perform this procedure. It should be sent out very soon, so please bear with us as we get it out to you.

    If you’ve sent Troy an email, he’s probably up to his ears in this right now, so please be patient in waiting on a response. Thank you to Matt and the rest of you for your support of the hobby!

  14. Kevin F
    Kevin F says:

    The sweet spot for my U-22 has changed over the 25 years I have owned her. At first it was around 3,000 rpm’s or 30mph. At that speed she is the most efficient for fuel use; the engine is at the magic 3,000 rpm’s for a 350 ci engine and the hull is out of the water more for reduced drag.

    After a decade or so, I slowed down to 2,100 or so, and around 20 mph, as I slowed down as well, and wanted a bit more quiet and softer ride.

    Now, unless it is mill pond smooth, I cruise around 1,400-1,600 rpm’s for a 14-17 mph cruise. At that speed, she is cutting the waves with her bow, and there is not any pounding regardless of the wave condition. I can then completely relax and not have to make constant wheel corrections to lift the chine up to reduce a wave smack. I can converse with the passengers more and not have to worry about how the boat is going to hit a wave.

    I do have the original bottom (with some replacement over the years), so as she and I are getting older, it seems to work to both of our advantage. No sense pushing 70 year old wood very hard.

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