1981 Evinrude 4.5 HP Bolt torque

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  • July 22, 2025 at 3:21 pm #298403
    outbdnut2
    Participant

      US Member

      I’m finishing up reviving an E5RCI ,  1981  4.5 HP Evinrude that hasn’t been run in 20 or 30 years for a friend.  Looks like the last person to change the impeller overtightened the impeller housing bolts, as two of the bolts have the plastic housing below it cracked.  When I get the new housing, what is the torque spec for those four bolts?

      Thx,

      Dave

      pump-housing-lo-res

      July 23, 2025 at 7:54 pm #298451
      crosbyman
      Participant

        Canada Member

        subjective question… if worried just   put some small star  lock washers and thighten down with extra 1/4 turn

         

        here is the chatgpt answer to your concern

        For the 1981 Evinrude 4.5 HP outboard, the torque specification for the water pump housing bolts is typically around 60 to 80 inch-pounds. That’s roughly 5 to 6.5 foot-pounds, so it’s a light touch—just enough to snug the bolts without cracking the plastic housing, which is a common issue if overtightened.

         

        Joining AOMCI has priviledges 🙂

        July 24, 2025 at 10:34 am #298475
        fleetwin
        Participant

          US Member

          Oftentimes, over torquing is not the issue here, especially in salt water.   The salt builds up between the metal sleeve and the plastic, which ends up splitting the plastic off.  Look closely at the other pieces as well, especially the plastic upper seal/bearing housing, this is fairly common.

          In any event, the torque spec is 60-84 inch pounds.  Be sure to use plenty of marine grease around those bolt shanks to help prevent/reduce the chances of this happening again.

          1 user thanked author for this post.
          Brent Bergen
          July 24, 2025 at 11:10 am #298477
          outbdnut2
          Participant

            US Member

            Thx guys for the torque spec and the info about saltwater.  With torque that small, I think I’ll use some thread-locker.

            When this motor was used, 25-30 years ago, yes – it was used in saltwater on the gulf off Florida, so that could have caused the pump housing to crack.  There was white granular stuff that came out on the bolt threads,  and not being a guy that sees saltwater motors, I assumed that dried up stuff was dried up thread-locker.  I’ll rinse out and lube the bolts and bolt holes.   I’ll do the same for the plastic seal above the gearcase.  I will not replace that if I can salvage it because new ones are $149.00!   There is a very small, partial crack in one corner of that which was could well have been caused, as Fleetwin said, by salt.   After each saltwater use, it was run for a while in a bucket of clean water.   I see no other signs of salt corrosion on this motor, and it’s new home will be on a lake in central Minnesota – so no more salt.

            Dave

            July 25, 2025 at 8:26 am #298507
            fleetwin
            Participant

              US Member

              Well first, don’t reuse that housing.  It will not clamp down properly with the plastic cracked like that.   $149??  No, that is not right.  $22.40 from marineengine.com

              https://www.marineengine.com/parts/johnson-evinrude-parts.php?year=1985&hp=8&model=E8RCOB&manufacturer=Evinrude&section=GEARCASE

              Finally, do not use thread lock on those screws.  60-84 inch pounds is plenty to clamp/hold the bolts in place.  Coat the threads and shanks of the bolts libearlly with marine grease to help avoid this problem in the future and to make sure you will be able to get those bolts out in the future without using the torch and melting all the plastic!

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