Announcement

Collapse
No announcement yet.

285 Mako Help with performance

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • 285 Mako Help with performance

    I have recently restored a 1988 285 Mako. It looks awesome but rides terrible. It takes a wave very soft but wants to steer all over the ocean. I have an Armstrong bracket with twin E-tec 250s. When it is calm in the river It rides pretty good. When it gets rough in the ocean it takes a big effort to keep the boat going in a straight line. When I added the engines and took them for the first test ride the boat really porpoised and rode very bow high. When I got it back to the dock I discovered that the last foot or so of the bottom of the boat was not straight flat. It had about a half inch of glass ground away. The corner where the vertical part of the transom meets the bottom of the boat was rounded as if it were ground down on purpose.I added glass to make the bottom flat and the corner is now pretty sharp. Water hits the engines at just the right spot and there is no porpoise at all. There actually may be a little down turn in the last couple of inches and I think this is where my problem is. I think this is keeping me from getting that huge bow up out of the water and that is where the steering problem is comeing from. It was a pain in the neck to add this material to the bottom of the boat and before I start grinding it away I was wondering if I was on the right track? If anyone has some ideas I would love to hear them. Thanks

  • #2
    I'll try to post some photos of the boat.


    Comment


    • #3
      Not bad for the first try.





      now lets see if two pictures show?

      Comment


      • #4
        Looks like an excellent restore. We definitely need more pics and "the rest of the story" for that beauty.

        If the first picture in the second post is "on plane", then I would definitely say the bow is low. My first thought would be to check the height of the engines with the bracket. The engines too low could cause the plowing and not enablng you to trim out without porpiosing too bad. But, you mentioned you checked that. Just for peace of mind, lay a 2x4 across the bottom of the hull extending out to the engines tilted down. The cavitation plate sould just be covered.... on a non bracketed setup. For the bracket, rule of thumb -->12" set back = 1" additional inch higher. So, 30" of set back = ~ 2 1/2" of additional engine lift (someone correct me if I'm wrong [] ).

        The "lip" you mention seems like it would act like trim tabs that are down. If it goes all the way across the back end, that's a big trim tab... [:u] When my tabs are down in rough seas I have that steering issue also.

        Now that advice will only cost you a few more action pictures and some performance numbers. []
        Artie Sutherland[br]Rude Attitude -\'76 Mako 25 CC. - SOLD[br]1976 Mako 21[br]2002 Yellowfin 31 - 300 hp Suzukis[br]Gulf Coast, Mississippi[br]

        Comment


        • #5
          Was it orginially set up as an inboard? I think the bow would be ok in that pic for a hull that weight and design, but Rude is definitely right that the lip on the transom would definitely act like a trim tab AND we definitely need more pictures and details! That is a beautiful boat. [][][]
          1978 Mako 25 - Blind Hog
          1985 Mako 20c - sold
          Fort Walton Beach, FL
          https://forum.classicmako.com/forum/...og-bottom-time

          Comment


          • #6
            OK more picturs to come. The boat was originally twin out boards

            Comment


            • #7
              What a BEAUTIFUL job you did on the restore [8D]
              quote:


              rides terrible. It takes a wave very soft but wants to steer all over the ocean.id="red">



              Sorry to hear your having problems! Did you get to run this boat in different sea conditions etc before you did the restore, so you can compare bracket vs non bracket performance? Maybe a prop change would help?

              I almost purchased an old 285 after spending two weeks in the Bahamas on one. The boat had 300 gal of fuel, fresh water and 6 people and gear on board. A pair of 225hp yamis with the original transom config. It was a mule through the water as you stated and tuff to get the bow up but had a soft re-entry in the snotty stuff. Great boat for the islands with the large beam, forward seats and twin consoles but not at the hole shot ..

              BTW: Your background pics tells me your in Martin county like me? I would love to see the boat up close some day!

              Good Luck
              Stuart, Fl

              Comment


              • #8
                One thing that comes to mind for me if you are having steering problems at speed is the toe angle of the engines. I see that you have a new pair of ETEC's (how are they doing by the way?) As a rule of thumb, Your engine's prop wash should meet together 75' behind the boat. Easy thing to do is to toss a regulation length ski rope over and see where the handle hits the wake, and adjust accordingly (handle @ prop wash intersection ideal). Improper twin engine alignment will make a boat that size very squirrely.

                Comment


                • #9
                  Sounds to me, from the pic, that the boat is "bow steering". On full plane, the sharp entry should not be in the water all the time. Sounds like the boat is light in the transom, a unique problem since most boats after being bracketed end up ass heavy.
                  1987 Mako 254, 2013 Evinrude ETEC 175\'s (sold to my buddy)[br]1988 Mako 20, 2008 Yamaha 200HPDI (sold)[br]1984 Mako 17, 2005 Suzuki 115 (sold)[br]1981 Mako 21 (sold)[br]1978 Mako 17 (sold)[br]1986 Mako 260 (sold)[br]1997 Mako 232 (sold)[br]Tampa, Florida

                  Comment


                  • #10
                    [quote]Originally posted by Empress III


                    One thing that comes to mind for me if you are having steering problems at speed is the toe angle of the engines. I see that you have a new pair of ETEC's (how are they doing by the way?) As a rule of thumb, Your engine's prop wash should meet together 75' behind the boat. Easy thing to do is to toss a regulation length ski rope over and see where the handle hits the wake, and adjust accordingly (handle @ prop wash intersection ideal). Improper twin engine alignment will make a boat that size very squirrely.

                    What is the toe angle? No way does my prop wash meet 75 feet behind the boat.[/quote

                    I'll try today with different trim angles but 75 feet seems like a long way back.]

                    Comment


                    • #11
                      quote:


                      There actually may be a little down turn in the last couple of inches and I think this is where my problem is.



                      That's called a "Hook" in the hull.

                      You can up your pix size to 640X480.

                      They are 512X330 now. It will fill out the page a little more, but not be to big.

                      Comment


                      • #12
                        That prop wash looks fine to me.
                        1987 Mako 254, 2013 Evinrude ETEC 175\'s (sold to my buddy)[br]1988 Mako 20, 2008 Yamaha 200HPDI (sold)[br]1984 Mako 17, 2005 Suzuki 115 (sold)[br]1981 Mako 21 (sold)[br]1978 Mako 17 (sold)[br]1986 Mako 260 (sold)[br]1997 Mako 232 (sold)[br]Tampa, Florida

                        Comment


                        • #13
                          The boat looks great!

                          The 28' Mako's from the 80's and early 90's were never known for their great performance, though it sounds like you're having excessive problems. Your situation reflects the challenges inherent in placing a bracket on a hull that was not designed for one -- in both single and twin applications. While mounting engines on a bracket may give the captain more room behind the console, the negatives often outweigh the advantages.

                          The mounting/placement of the bracket, as well as the style of bracket has a tremendous impact on the performance of the hull after installation. I have a couple of friends who mounted Armstrong brackets on their Mako's (both single engine configuration) and they ruined their boats.

                          Would recommend taking the boat to a respected marine boat yard in your area and get their input on both the installation of the bracket and the engines. There's no location in your profile, so it's tough to recommend a boatyard. If you're here in West Central FL, I've got some recommendations. It may require reinstalling the bracket and engines, but if if solves the problems -- great!

                          Good Luck,

                          Tom
                          Prop Blast[br]Mako 224, F225[br]Tampa, FL

                          Comment


                          • #14
                            Definite bow steer. Some things to look at:

                            - are ya propped right

                            - Engine height

                            I would like to see a couple pics of that transom repair. Sure sounds like ya got some hook.........use a long straight edge and verify the bottom of the hull is straight all the way back, pay particular attention to the area that was filled in. I have a very stinky feeling that adding that glass messed things up. 5 degrees of hook across the back would sure f things up. Do ya have tabs ?? I would probably grind that fix off, and add tabs, that way you can make attitude adjustments as nessasary.

                            Comment


                            • #15
                              Definite bow steer. Some things to look at:

                              - are ya propped right

                              - Engine height

                              I would like to see a couple pics of that transom repair. Sure sounds like ya got some hook.........use a long straight edge and verify the bottom of the hull is straight all the way back, pay particular attention to the area that was filled in. I have a very stinky feeling that adding that glass messed things up. 5 degrees of hook across the back would sure f things up. Do ya have tabs ?? I would probably grind that fix off, and add tabs, that way you can make attitude adjustments as nessasary. If the hull is right, motor height right, propped right and tabs, that hull should perform pretty good.

                              Comment

                              Working...
                              X