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  • Repowering - Engine Weight v. HP?

    Newbie here!

    I've got my eye on a couple '72-'73 Mako's, all 22-23'. I'm trying to factor in the cost to repower. I've read other posts saying to ignore the manufacturer's "Max HP" plate (230hp for '72 22' and 250hp for '72 23' https://www.makoboats.com/past-model...tBoatYear=1972 ).

    It looks like engines have a seen some bloat over the years:

    1984

    Yamaha 150hp = 395lb

    Yamaha 200hp = 400lb

    Yamaha 220hp = 405lb

    2016

    Yamaha 115hp = 377lb

    Yamaha 150hp = 478lb

    Yamaha 200hp = 487lb

    Yamaha 225hp = 505lb

    Yamaha 250hp = 505lb

    http://www.nadaguides.com/Boats/2016...utboard-Motors

    My question for the group: what's more important to consider, the engine HP/thrust or the engine weight?

    Put another way, should I assume a 1972 22' is still capable of 230hp (or less, given recalculation of HP), or should I assume it's only capable of an engine weighing about 400lb?

    Thanks!

  • #2
    Just an assumption, but you are comparing 1984 2 strokes to 2016 4 strokes.

    The 4 strokes are all heavier.
    1984 Mako 228 w/ 175hp E-Tec [br]1983 SeaRay 26\' Sundancer w/ 454 Big Block spinning Volvo DuoProps (Sold)[br]1989 Wahoo 17\' CC w/ 88hp Evinrude (vacationing in Key West)[br]

    Comment


    • #3
      I'm not going to comment on whether to ignore the Max HP rating or not. However, I will say that many dealers, at least those in South Florida, will not sell you a 300HP engine to throw on the back of a boat rated for 250HP. They basically claim liability issues. This is despite the fact that a 300HP engine (typically the same block as a 250HP) weighs the same.

      To give you a comparison... I own a 221B that is significantly heavier than the '72 Mako 22. The dry weight difference is 800 lbs. I also carry three times the fuel. On the 221B I had a 1992 Yamaha and later a 1999 Yamaha 225 HP, both two strokes. The boat cruised comfortably on plane at 3800 to 4200 RPM and hit 42 to 43 MPH at 5200 to 5300 RPM.

      I am in the midst of a getting a new engine on there. I did the homework on the weights to see what the differences where. I have different figures compared to what you showed. A 2016 200HP Yamaha shows at 505 lbs but that's an inline 4. The 2016 225 moves to a V6 and weight comes to 560 lbs.

      From my homework:

      1999 Yamaha 225 HP, OX66 Outboard weight was 495 lbs. That was just engine. To that add the 15 lbs the hydraulic steering piston weighs. That puts us at 510 lbs in back.

      2018 Yamaha 225HP or 250HP weighs in at 551 lbs and I must use the steering piston. That brings us to 566 lbs in back.

      2018 Evinrude E-Tec G2 250 H.O. weighs in at 537 lbs but has power steering built into the engine. In short, no need for the steering piston. That means 537 lbs in back.

      I went Evinrude for a few reasons but won't hijack your thread.

      Getting back to your specific needs. I would tell you that, because of your boat dry weight, I'd say you would be quite happy and comfortable at 200HP or 225HP. At 200HP you should be at a top speed near 40 MPH propped correctly. I'd be more looking at the HP rating and getting the right prop than worrying about the weight. Most V6 engines hover in the same range for 200HP to 250HP. 2 strokes being lighter.
      Luis V.[br]1992 Mako 221B & 2018 Evinrude E-Tec G2 250 HO

      Comment


      • #4
        Also, the "Max HP" ratings up until ~1981-84 (phased in) were all measured at the powerhead of the motor--so the rating at the prop, where it's done today, was lower. From what I've seen posted elsewhere, people think it's a 5-10% difference.
        NYC & L.I. - 1974 \"Classic\" Mako 20\' - Suzuki 2006 DF150 - Fly & Light Tackle, C&R[br]My boat: http://www.classicmako.com/forum/topic.asp?TOPIC_ID=23444#159594[br]Personal website: http://www.georgemcauliffe.com/

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        • #5
          Check out the new Mercury 225hp Four Stroke at 450lbs.

          Comment


          • #6
            For what its worth, I have a '72 Mako 22' that originally had a OMC 150 on her and was re-powered (before I got her) to a '87 Suzuki 150 that had some fuel starvation issues. My adopted motto now is "2 old motors is better than 1 old motors" and acquired 2 '86 Yamaha 115s from Pete (on this board ... or at least use to be) and have mounted them on the back of the boat. My concern is that the boat sits a little low in the water now, but I have not redone the floor yet and am pretty sure that I have wet insulation. That project is due when I get my new garage built, hopefully by the end of the summer. My original sea trials were good though and the boat got up on plane easily and cruise with near perfect control.
            72\' Mako 22\'[br]NoNeck, VA

            Comment


            • #7
              For what its worth, I have a '72 Mako 22' that originally had a OMC 150 on her and was re-powered (before I got her) to a '87 Suzuki 150 that had some fuel starvation issues. My adopted motto now is "2 old motors is better than 1 old motors" and acquired 2 '86 Yamaha 115s from Pete (on this board ... or at least use to be) and have mounted them on the back of the boat. My concern is that the boat sits a little low in the water now, but I have not redone the floor yet and am pretty sure that I have wet insulation. That project is due when I get my new garage built, hopefully by the end of the summer. My original sea trials were good though and the boat got up on plane easily and cruise with near perfect control.
              72\' Mako 22\'[br]NoNeck, VA

              Comment


              • #8
                I own a 1973 22 footer. I freshened up, repainted, and hung a low hour 1978 Evinrude 235 that I got from a fresh water lake boat on the back. It is near dead on 400lbs. That 235 (pre early 80s shaft hp) is likely more like 200 prop hp. The boat is very lightly rigged. Two group 24 batteries aft in the hull, a light aluminum fortress anchor fwd, no T-top, factory concole and modest leaning post. The bottom is painted with Aquaguard over a 4 layer sanded epoxy barrier coat, its prety smooth for a painted bottom. With an OMC Renegade 17 pitch 4 blade prop, she leaps onto plane and maxes out at 48 mph (gps) @5700rpm with about half tank of fuel. With the Viper 19 pitch 3 blade, a small trade in launch for a small gain in top end.

                One minor issue I have is for the given power/ weight of the engine, I am having a hard time getting the boat to keep the bow up at speed. I added 200lbs of sandbags to the splash well as an experiment and it did help trim out the boat a bit. It dropped the waterline at the transom nearly 1.5 as well. Id think these boats, assuming the transom and floors are in sound shape, would trim out better with a heavier outboard out back.

                Im at 400 lbs for an engine and 100lbs for the two batteries, and IMHO its too light back there for the power and speed the boat runs. Im considering remounting my engine to a 6 setback fixed bracket to leverage the engine weight back a bit further. I should be able to have the prop drive angle inline with the bottom of the keel and trim about right. I currently need to trim up quite a bit more than that and the bow lift is still marginal(and Im using bow lifting props)

                The Mako 22 was designed to handle two 115hp OMC v4 engines, at +/- 300lbs a piece, so 600lbs plus the two batteries back there. So 700lbs was the weight at the back end the boat was designed around for the 230hp max limit.

                Im 200 lbs short on that and it shows. To be fair I am also running the boat a bit faster that it was intended as well by a few mph.

                Most modern 200+hp engines are going to be 25 shaft, rather than the 20 of the hull. This creates issues. Totally rebuilding the transom properly and raising the transom height to 25 at the same time would be about ideal. Adding a modern heavy (500-600lb) 4 stroke 200+ hp engine would likely be a great combo for the boat. You can always move the 100lbs worth of batteries to under the console if desired.

                George

                Comment


                • #9
                  I own a 1973 22 footer. I freshened up, repainted, and hung a low hour 1978 Evinrude 235 that I got from a fresh water lake boat on the back. It is near dead on 400lbs. That 235 (pre early 80s shaft hp) is likely more like 200 prop hp. The boat is very lightly rigged. Two group 24 batteries aft in the hull, a light aluminum fortress anchor fwd, no T-top, factory concole and modest leaning post. The bottom is painted with Aquaguard over a 4 layer sanded epoxy barrier coat, its prety smooth for a painted bottom. With an OMC Renegade 17 pitch 4 blade prop, she leaps onto plane and maxes out at 48 mph (gps) @5700rpm with about half tank of fuel. With the Viper 19 pitch 3 blade, a small trade in launch for a small gain in top end.

                  One minor issue I have is for the given power/ weight of the engine, I am having a hard time getting the boat to keep the bow up at speed. I added 200lbs of sandbags to the splash well as an experiment and it did help trim out the boat a bit. It dropped the waterline at the transom nearly 1.5 as well. Id think these boats, assuming the transom and floors are in sound shape, would trim out better with a heavier outboard out back.

                  Im at 400 lbs for an engine and 100lbs for the two batteries, and IMHO its too light back there for the power and speed the boat runs. Im considering remounting my engine to a 6 setback fixed bracket to leverage the engine weight back a bit further. I should be able to have the prop drive angle inline with the bottom of the keel and trim about right. I currently need to trim up quite a bit more than that and the bow lift is still marginal(and Im using bow lifting props)

                  The Mako 22 was designed to handle two 115hp OMC v4 engines, at +/- 300lbs a piece, so 600lbs plus the two batteries back there. So 700lbs was the weight at the back end the boat was designed around for the 230hp max limit.

                  Im 200 lbs short on that and it shows. To be fair I am also running the boat a bit faster that it was intended as well by a few mph.

                  Most modern 200+hp engines are going to be 25 shaft, rather than the 20 of the hull. This creates issues. Totally rebuilding the transom properly and raising the transom height to 25 at the same time would be about ideal. Adding a modern heavy (500-600lb) 4 stroke 200+ hp engine would likely be a great combo for the boat. You can always move the 100lbs worth of batteries to under the console if desired.

                  George

                  Comment


                  • #10
                    I own a 1973 22 footer. I freshened up, repainted, and hung a low hour 1978 Evinrude 235 that I got from a fresh water lake boat on the back. It is near dead on 400lbs. That 235 (pre early 80s shaft hp) is likely more like 200 prop hp. The boat is very lightly rigged. Two group 24 batteries aft in the hull, a light aluminum fortress anchor fwd, no T-top, factory concole and modest leaning post. The bottom is painted with Aquaguard over a 4 layer sanded epoxy barrier coat, its prety smooth for a painted bottom. With an OMC Renegade 17 pitch 4 blade prop, she leaps onto plane and maxes out at 48 mph (gps) @5700rpm with about half tank of fuel. With the Viper 19 pitch 3 blade, a small trade in launch for a small gain in top end.

                    One minor issue I have is for the given power/ weight of the engine, I am having a hard time getting the boat to keep the bow up at speed. I added 200lbs of sandbags to the splash well as an experiment and it did help trim out the boat a bit. It dropped the waterline at the transom nearly 1.5 as well. Id think these boats, assuming the transom and floors are in sound shape, would trim out better with a heavier outboard out back.

                    Im at 400 lbs for an engine and 100lbs for the two batteries, and IMHO its too light back there for the power and speed the boat runs. Im considering remounting my engine to a 6 setback fixed bracket to leverage the engine weight back a bit further. I should be able to have the prop drive angle inline with the bottom of the keel and trim about right. I currently need to trim up quite a bit more than that and the bow lift is still marginal(and Im using bow lifting props)

                    The Mako 22 was designed to handle two 115hp OMC v4 engines, at +/- 300lbs a piece, so 600lbs plus the two batteries back there. So 700lbs was the weight at the back end the boat was designed around for the 230hp max limit.

                    Im 200 lbs short on that and it shows. To be fair I am also running the boat a bit faster that it was intended as well by a few mph.

                    Most modern 200+hp engines are going to be 25 shaft, rather than the 20 of the hull. This creates issues. Totally rebuilding the transom properly and raising the transom height to 25 at the same time would be about ideal. Adding a modern heavy (500-600lb) 4 stroke 200+ hp engine would likely be a great combo for the boat. You can always move the 100lbs worth of batteries to under the console if desired.

                    George

                    Comment


                    • #11
                      George,

                      Raising the trim would raise the bow. Most guys are trying to push it down to cut through the chop.
                      1984 Mako 228 w/ 175hp E-Tec [br]1983 SeaRay 26\' Sundancer w/ 454 Big Block spinning Volvo DuoProps (Sold)[br]1989 Wahoo 17\' CC w/ 88hp Evinrude (vacationing in Key West)[br]

                      Comment


                      • #12
                        With the fine trim all the way up, there is still very little bow lift. Even with 200lbs worth of sandbags at the transom.

                        George

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