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Opinion on crank journal..

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  • Opinion on crank journal..

    Journal is smooth and mics on specs, not oval or tapered.. Is this ok to use?
    main between cyls #1 and #2

  • #2
    What is the crank out of. Plain or roller bearings?
    BOAT SPECS FORUM HELP STARCRAFT FORUM SHOP iboats
    Please, no PM's (Private Messages) regarding boat/engine problems.
    That is what the forums are for.
    Only forum/moderator issues will be answered in PM's.

    Comment


    • #3
      125hp 4cyl force outboard, 2cycle cross flow, roller bearings
      1258X5A
      Last edited by rk970; October 5th, 2017, 10:34 PM.

      Comment


      • #4
        Not 100% okey but I should go for it if you do not have put a lot of money in it.

        If you have rebore and put in new pistons ...... look for a better used crank.
        I would not be satisfied with that crank with a rebored block and new pistons.


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        • #5
          Use it.


          Buy American made Cars and Trucks!!!Towing insurance for a boat,a GREAT thing.
          ​Tools to make my life easier: Battery tester, die grinder, temp.gun, compression tester, DVA meter.

          In Scenic , Beautiful San Sebastian by the sea Florida

          88 Bayliner 21CC 2001 Mercury 225 HP EFI

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          • #6
            I decided to try to find a better crank.. The force 125 crank part #FA528018 has been superseded to part # 817400T3
            I found a local crank from a 1992 force 120, when I looked up the part number for the crank it is 817400T3. I cannot confirm anywhere if the stroke on a 1992 120 is indeed 2.875". I went and looked at the crank its in perfect condition with all bearings and he is asking $60 for it..
            Can some one confirm what the bore/stroke on the 1992 120hp are, it is a 15 spline crank and it has the force lower unit.

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            • #7
              You'll need to get the factory manual to find the stroke.

              ​IF??? my memory is right 1992 they used 2 different size pistons.
              The crank can be used on 1990-1994 model blocks.

              I would bet the 90's crank is the 2.875

              The manuals I have show the 86 is 2.80 and everything in the 90's is the 2.875

              ​BUT!! I don't have a manual for the 90's 120.
              ​I'm comparing a manual for a 86/125 and a 90's 150.

              ​The old crank: does it catch a fingernail in the holes when you touch it?
              ​From the look?? If it doesn't have ridges on the holes? It should be ok to use.



              Buy American made Cars and Trucks!!!Towing insurance for a boat,a GREAT thing.
              ​Tools to make my life easier: Battery tester, die grinder, temp.gun, compression tester, DVA meter.

              In Scenic , Beautiful San Sebastian by the sea Florida

              88 Bayliner 21CC 2001 Mercury 225 HP EFI

              Comment


              • #8
                Originally posted by jerryjerry05 View Post
                You'll need to get the factory manual to find the stroke.

                ​IF??? my memory is right 1992 they used 2 different size pistons.
                The crank can be used on 1990-1994 model blocks.

                I would bet the 90's crank is the 2.875

                The manuals I have show the 86 is 2.80 and everything in the 90's is the 2.875

                ​BUT!! I don't have a manual for the 90's 120.
                ​I'm comparing a manual for a 86/125 and a 90's 150.

                ​The old crank: does it catch a fingernail in the holes when you touch it?
                ​From the look?? If it doesn't have ridges on the holes? It should be ok to use.
                I measured the stroke on my 1985 125hp (1258x5a) at 2.87* I have a 908h4b (84 4cyl 90hp) and that stroke measured at 2.80*.
                I cleaned the rod journal and main with 800, then looked at it under 20x magnification. There are a lot of pits, some areas I can feel "catch" with a finger nail.. Some areas between the pits have what look like micro fracturing of the surface. The rollers and bearing shell from that main have the same appearance.
                I have done some mild porting on the transfer ports and a new set of pistons going in. I just got a bad gut feeling on running this crankshaft..

                Comment


                • #9
                  I would go by your "gut feelings" And try to find another crank.

                  Comment


                  • #10
                    Follow the gut!!


                    Buy American made Cars and Trucks!!!Towing insurance for a boat,a GREAT thing.
                    ​Tools to make my life easier: Battery tester, die grinder, temp.gun, compression tester, DVA meter.

                    In Scenic , Beautiful San Sebastian by the sea Florida

                    88 Bayliner 21CC 2001 Mercury 225 HP EFI

                    Comment


                    • #11
                      FYI the 1992 120hp crank is indeed 2.875" stroke..

                      Comment


                      • #12
                        Sign up today
                        Now the tough part, trying to remember that!!

                        ​I can remember pretty much everything I did up until I hit 55 .
                        ​Now!! I can't remember what I had for breakfast!!!!


                        Buy American made Cars and Trucks!!!Towing insurance for a boat,a GREAT thing.
                        ​Tools to make my life easier: Battery tester, die grinder, temp.gun, compression tester, DVA meter.

                        In Scenic , Beautiful San Sebastian by the sea Florida

                        88 Bayliner 21CC 2001 Mercury 225 HP EFI

                        Comment

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