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'82 Mako 20B

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  • '82 Mako 20B


    First post here after lurking and figured I should document the progress.

    The adventure started on Thanksgiving 2017 when I bought a new to me 1982 Mako 20B with a 99 Johnson 150.

    From my inspection, I had a short term / long term list of projects it would need.

    New Wiring

    New Tank

    Replace teak console trim with starboard

    Bilge Pump

    Light LED conversions

    Add an above deck live well with plumbing

    Simrad GO7 GPS

    New Cushions

    New Gauges w/ replacement of console

    Add a kill switch

    New trailer tires and bearings (after a blow out on the way home from the Keys!)

    Mid/Long Term

    -Fixing some "love scuffs" from what I assume was a dock encounter.

    -Transom repair due to unprotected/poorly protected openings. Transom had minor cracks which wouldn't move when I bought so I decided I would watch.

    -Paint after all the glass work got done.

    Got to work on the major stuff to try and get her out.

    First time at fiberglass, looks good enough to give me confidence and make me dangerous!

    The day came to finally take her out. Had some findings after the shakedown.

    She floats!

    Makeshift console door looks pretty ghetto! New cushions are needed.

    She catches fish!

    Other items:

    - Anchor locker door would fall underway (make a latch)

    - Steering tab on motor was positioned wrong

    - Took on water through scupper holes while anchored. This would travel through the pie plates which had bad gaskets and turn on bilge. When we would get in the back, water would come over more and go into the in floor cooler. There, a bag or fish could clog the drain and add significant weight, thus making the cycle worse and really making her squat. My first step was to put scupper balls and new pie plate gaskets to see if this helped

    More work pics:

    Livewell/washdown concoction. Not too happy with washdown pressure so I may need a dedicated pump or go the KISS route and just live with it and use a bucket if extra water is needed.

    Second trip was farther offshore but revealed some more work

    - One of the sides had a rattle and seemed loose. Taking off the rub rail showed that the rivets were mostly gone on that side. Should be an easy fix

    - The transom cracks got bigger and now it would move when I jumped on it. This kicked off the mid range portion of the rebuild after 2 trips!

    Motor removed

    Getting preped for surgery

    What was hiding under the aluminum angle

    Aluminum has a down and back bend to it. Not sure if this was original or a result of the engine weight.

    Now on to the transom plan:

    - Cut outer skin

    - Dig out wood

    - Inspect/dig out stringers

    - Build inner/outer splash guard skins

    - Attach splash guards and patch everything with mat/glass/matt on inner skin, mat/glass/mat on outer skin using West Systems

    - Reattach outer skin and seal tops of engine well

    - Pour Arjay through open tops of splash guards

    - Glass over top of skins

    Any thoughts on this process? I've read about an issue using West and Arjay together somewhere but can't find anything else confirming this to be an issue.

    For water intrusion, scuppers and gaskets only helped in the bay. Offshore, with us in the back, waves would come over the top and into the large in floor cooler. This cause the bilge to turn on (less than before) and melt all the ice. Plan was to seal the fold down transom door and install scupper drains on that wall. Hopefully this keeps any water that does come in sealed between the transom and the door while keeping the inside self bailing. End results I'm shooting for something like Ron Garrett did on the project boat section.

    After all this is done, plan is to patch and repair remaining glass around boat exterior, paint, and redo rub rail. Thoughts for paint I've bounced around:

    Option 1 ($): Vivid white on bottom, EMC Genius Ice Blue on topsides and splash well, and leave decks as is (spider cracks and all) all rolled

    Option 2 ($$): Vivid white, EMC Ice Blue Topsides, and TBD White on decks and above rub rail all rolled

    Option 3 ($$$): Same color scheme sprayed by a pro in some Awlgrip/Awlcraft combo

    Any input from experience? I haven't painted or paid for painting, so input would be appreciated. I'm currently thinking I want to keep the boat for at least 5 years and then consider an upgrade. Figure that any paint job wouldn't have much resale at that point so as long as the paint looks good from far, I can live with it and then go pro route if needed later.
    [br]\'82 Mako 20B

  • #2
    Alot of progress done so far. Sucks only two trips before full tear down but that's classic boats for you. The only peace of mind that (thinking I can speak for everyone on this site on this) we know what we have when all said and done. The project will be overwhelming but just take it step by step.

    That being said,

    Is that rubber gasket material you put in the tank coffin or neoprene?

    Rubber will attract moisture and kill the tank quickly..

    Did you pour foam under the coffin in those holes to support the coffin/tank. They look empty in the picture.

    I like the engine stand I built 2 just like it from plans online! 30$ all in is alot better then buying one for a few 100$

    How long is the engine shaft? Maybe think about raising your transom another 5" and going with a longer shaft engine to keep the seas out?

    How is the live well plumbing penetrating the deck? Open to the bilge or on top of the fuel tank?

    From your name I take it your in South Florida, check out FGIC

    Off of Stirling Road and I95. Ask for senior and pick his brain. Great guy.
    Fort Lauderdale, FL[br]1990 231 Mako[br]1998 Keywest 1720[br][br][br][/url]


    • #3
      Hi Make,

      I went with neoprene strips. I also added 2 additional blocks since I didn't want to do the foam. My brother just redid his 25 Rampone (Seavee) tanks with foam. Hopefully we can compare results in 25 years!

      I didn't pour new foam under but I didn't take much out either. I took out the big chunks that were seriously waterlogged and then ran a PVC front and back to create a channel under the foam for water to run easily.

      Engine stand was great. I went pressure treated so cost ended up at $75. Maybe it last long enough for an eventual repower.

      Engine is a 20". I thought about raising to a 25" but wasn't sold that an extra 5" would really achieve what I want. Tossed around the bracket idea but heard of too many people saying no way on a boat this size.

      Livewell plumbing was interesting. Initially I tried to under the in deck cooler but the route there proved impossible. Ended up running in and out of the in floor cooler edge using PVC chases epoxied to fiberglass. Water doesn't get close to fuel tank. Exit goes through an existing 1" thru hull which I added a seacock to.

      This is the large cooler I couldn't get around.

      If you meant the large storage in the front, I'm guessing it goes to the bilge because I didn't see anything running inside the coffin.

      I'll have to check FGCI out. Just online shopping was between them and Merritt for the Arjay but would like to do a local pickup to save on shipping, bounce ideas, and get other supplies.
      [br]\'82 Mako 20B


      • #4
        Progress Report:

        Got back to the grind (pun intended) to get the transom skin and core off. Plan was to leave a 4" lip on either side for glass.

        A bit of gentle coaxing and off came the skin.

        After that it was on to removing the wood. Parts had me wondering how she got us back home while others had me amazed at how hard the wood was even after that moisture.

        After this, I was left with a couple questions:

        1. How to get out the wood between the lip? Buy an electric chainsaw? Keep hacking with hand tools?

        2. Stringers are partially exposed in transom and seem to be sealed with glass. Inside, only the center one has a penetration for a drain hole. I can't tell if it was epoxied, but I cant get anything out of it with a screwdriver. Should I let it dry and glass it up, drill out cores and let the Arjay flow in, or cut into the lip and dig it out with a chainsaw/sawzall?

        3. Bottom motors holes where enormous and filled with some type of marinetex. Guessing that was a patch job from when it was repowered in 99. Back side has an odd shape with anther brace so still thinking about how to address. Thoughts?
        [br]\'82 Mako 20B


        • #5
          Try a Lancelot attachment on your 4in grinder. But please be careful it kicks back nasty and it's spinning insanely fast. Find them on Amazon or harbor freight sells a knock off that works well.

          Just keep it off the fiberglass or the blade will be dull quickly.


          I strongly suggest raising your transom 5in and going with a 25in shaft motor. Keeps the seas out, motors power head is further away from the water.

          You can really see the difference here on my transom. I went from 25in to 30in

          Get a peice of cheap formica board with a finished side, measure the transom 5in up on both sides. Secure the board at the 5in mark on the inside skin (since your working from the outside) spray the crap out of it with pva. Let it dry then lay on the glass. When you re core it's all one structure.

          Fort Lauderdale, FL[br]1990 231 Mako[br]1998 Keywest 1720[br][br][br][/url]


          • #6
            You can use the tool suggested above, but it is really tough to keep hold on it. I liked the electric chainsaw when I did mine.

            I would let the stringers dry up a little bit and see what they look like. If they do not move with a screwdriver, then epoxy coat them and move on.

            The large holes you obviously have to patch with fiberglass cloth since you are pouring. Make sure you have no holes.

            I did not pour my transom but it seems that stuff will find the holes!
            \'07 Mako 19 bay, sold[br]\'76 Mako 21, sold[br]\'77 Mako 21, dump[br]\'77 Mako 22, sold[br]\'80 Mako 23 WA, sold[br]\'82 Mako 21, sold[br]\'85 Mako 254 currently[br]\'78 J24 USA 292 (sold)[br]\'05 Melges 32 racing sailboat


            • #7
              Kicking around thoughts on the wood removal is leading me to the electric chainsaw. I might have one I can borrow, maybe get a cheap one under $50, and seems like there's more to hold on to to control the cut.

              For raising the transom, I keep weighing options and everything has pros/cons.

              Keep at 20" with new splash guards:




              -No mods to current motor or repower needed

              -Performance should ride the same, with less water thanks to splash guards


              -Least wave protection

              -Less desirable repower options if/when that comes

              -Future 25" motor would need an add on splash guard and a jack plate to achieve the same results as a 25"

              25" with splash guards


              -Low point is 5" higher than today

              -More attractive repower options


              -Need to repower or mod motor

              -More time and money

              -Might leave me wishing I had a closed transom (sell/bracket) for a true offshore boat




              -Clean transom




              -Performance unproven or undesirable

              If I had doubts in the motor and was going to repower anyways, I'd go to 25" and hope for the best. However, with time and cost being factors, I can't see an optional repower coming before I get the wife and kids hooked on going out on the boat[].

              On the water over the transom, I feel like my biggest concern is keeping it above deck. I know it's coming in through the fish box. Plugging the fish box just fills it with water and gives a real bad squat to it while anchored. Are there any ideas on keeping water between the transom and the folding splash guard only?

              For the mounting holes, the inside has an odd shape goop of material which looks like it was used to glue down the deck. My thoughts are the big washers should be enough for these bottom holes and then I'd use one of those aluminum bar support plates for the top bolts.


              To patch the holes, should I use epoxy or polyester resin? I like that epoxy is stronger for fiberglass repairs but am hesitant with the future Arjay pour. When I add glass and resin before the pour, should epoxy be avoided? What about after the pour to put the final glass on the outside? I might just need to call or swing by FGCI and make sure I'm thinking things right.
              [br]\'82 Mako 20B


              • #8
                Maybe look into extending the motor you have now?

                I owned a 22 awhile ago that the transom had been redone, and then they repowered with a 25" motor and put a 5" taco aluminum plate on the transom that looked horrid.

                My 254 came with about 5" from the waterline to the transom and the first time I was in 2' waves I felt uncomfortable. I would highly recommend raising it now. The for now fix will not be the best in the end and it is easy to add that 5" now.
                \'07 Mako 19 bay, sold[br]\'76 Mako 21, sold[br]\'77 Mako 21, dump[br]\'77 Mako 22, sold[br]\'80 Mako 23 WA, sold[br]\'82 Mako 21, sold[br]\'85 Mako 254 currently[br]\'78 J24 USA 292 (sold)[br]\'05 Melges 32 racing sailboat


                • #9
                  Hi Scott,

                  I've kicked that one around too and see two ways to get that done.

                  - Bay Mfg extension kit 507. Filled out their for to see if I get a response.

                  - Swap out parts with a 25". This was my initial thoughts as my brother has a broken down 96 150 Evinrude that I could salvage. Although this seems like a slam dunk, he swapped his lower unit on that motor before it broke down. The lower unit he bought was just barley too long and the mechanic at the time suggested he could shave down the shaft. After that, it seemed to fit, but not long after the engine stopped working. He suspects the shaft was still too long and putting pressure against the motor. That said, if I went this route and went to reuse parts, what would I need? Shift shaft, water tube, housing, longer bolts? As for the drive shaft, I get different part numbers online and no clarity as to which is the 20" for a J150PLEES and which is a 25" for a J150PXEES.
                  [br]\'82 Mako 20B


                  • #10
                    too long a shaft should destroy the lower unit before it hurts the powerhead. have you separated them to see which has the issue?
                    76 25 \"Aenigma\"[br]73 17[br]Richland/Long Beach, MS[br][br][br]17 project[br]


                    • #11
                      Not a big fan of the aftermarket extension kits, plus there somewhat pricey for what you get. You can swap out your lower unit driveshaft and shifter shaft for a 25" driveshaft/shifter shaft. Water tube is in the midsection. Your going to break the retainer in your lower unit when you remove the driveshaft, but don't worry about it. The driveshaft doesn't move once it's seated into the crankshaft. You could also sell your lower and swap it out for any Johnson or Evinrude 25" lower unit. I think the 90 degree loopers have a 1/4" longer driveshaft than the 60 degree loopers,I think.[] We just cut the top down and bevel the driveshaft on a belt sander.
                      1978 Mako 21[br]Schneider [br]Butler, PA


                      • #12
                        Got the chainsaw and it worked out great. Was able to get far into the corners and leave everything clean. Left stringer had a hollow spot about a finger deep and then hard wood. The other two were wet but hard so plan is to let em dry then coat in glass and resin. After that, more sanding.

                        On the motor, I've gone back and forth on this all week. I want to get it wrapped up and remove variables, but I also don't want to regret not raising it after I pour. For now, my plan is to get my brother's 25" lower and mid section, assemble in on the stand, pull my power head, and compare how far the driveshafts extend compared to each other. I was thinking that they should be the same length from the mid section to the power head and that if the 25" shaft is longer, it might be that the previous mechanic did not grind it enough. Is my thinking right on? Really don't want to break my power head using the middle and lower off an engine that broke a power head shortly after having the lower replaced.
                        [br]\'82 Mako 20B


                        • #13
                          The only way a lower unit is going to damage a powerhead is if the driveshaft was way to long and it pushed the crank up into the block when the lower unit bolts were snugged up. If I didn't enclose my transom I would have made my motor a 30" shaft length, but I went enclosed and used an Armstrong bracket. Put a layer of resin and cloth over the stringers and inside of your transom so you don't get leaks like me.[] The flicker link below has pictures from when I did mine.

                [email protected]/
                          1978 Mako 21[br]Schneider [br]Butler, PA


                          • #14
                            The extension kits are stupid expensive. I believe they told me $825 per set.

                            If you have a lower and a shift shaft you are 90% there. Pull and replace the midsection or swap powerheads with the other motor.

                            I would think with the bearings holding the powerhead in place, you would break the gearing in the lower unit before destroying the powerhead.
                            \'07 Mako 19 bay, sold[br]\'76 Mako 21, sold[br]\'77 Mako 21, dump[br]\'77 Mako 22, sold[br]\'80 Mako 23 WA, sold[br]\'82 Mako 21, sold[br]\'85 Mako 254 currently[br]\'78 J24 USA 292 (sold)[br]\'05 Melges 32 racing sailboat


                            • #15
                              You are doing all this work, I would definitely raise the transom. Your boat is a fairly rare model as well. It has the newer design interior except the rear fish box. My '85 and later versions had an in floor livewell and was the "20c". I would also look for a dual axle trailer. You are pushing the limits with a single. You can replace the rabud pie plates to prevent bilge leaks but a rectangular hatch would be even better.
                              1978 Mako 25 - Blind Hog
                              1985 Mako 20c - sold
                              Fort Walton Beach, FL