Home Forum Ask A Member 1950s Evinrude 7.5 hp

Viewing 10 posts - 1 through 10 (of 12 total)
  • Author
    Posts
  • #1939
    mgsolakis
    Participant

      I’ve got a 1950s Evinrude 7.5 hp and I tested compression today and it’s even at just over 60PSI according to my gauge. Does that sound ok?

      #19490
      fleetwin
      Participant

        US Member - 2 Years

        Well, kind of a marginal reading, but that may just be due to gage inaccuracies or a dry engine. I would attempt to get the engine running then retest. 75PSI is a normal reading for these engines.

        #19493
        Doug Wilson
        Participant

          US Member - 2 Years

          that is about what my 5.5hp tested after setting many years but it seems to be running great anyway

          Doug

          how is it motors multiply when the garage lights get
          turned off?

          #19558
          20mercman
          Participant

            US Member

            Well, I am fairly fond of our 1950 Fleetwin. We converted it to modern coils, as the originals were melted as they almost always are. After that, and some other work and an impellor, it is a very nice motor. Our 53 is back on the rack for now as I am frustrated with trying to solve a vibration problem.

            Steve

            #19559
            wedgie
            Participant
              quote 20mercman:

              Well, I am fairly fond of our 1950 Fleetwin. We converted it to modern coils, as the originals were melted as they almost always are. After that, and some other work and an impellor, it is a very nice motor. Our 53 is back on the rack for now as I am frustrated with trying to solve a

              quote :

              vibration problem.

              Steve

              What are your symptoms ? My ’54 rattled until I shimmed the front starter hold down screws.

              Sorry to hijack this thread 🙄

              60 psi is pretty low. The numbers might come up with a de-carbon, or with a 50 cent hone job.

              #19560
              20mercman
              Participant

                US Member

                It idles and runs fine at slow speed, above half throttle, it starts to shake, and any more throttle and shakes so bad that you can’t run it. It has a brand new crank from Chinewalker, +.020 over bore and rebuilt ignition system. I was planning to swap the lower unit to rule that out, just have not gotten around to it. I am afraid I have a balance problem in the powerhead.

                Steve

                #19563
                mgsolakis
                Participant

                  Would a 50 cent hone job not require oversized rings a well?

                  #19564
                  20mercman
                  Participant

                    US Member
                    quote mgsolakis:

                    Would a 50 cent hone job not require oversized rings a well?

                    Is this question about whether it has the correct pistons and rings? If so, yes, it has the correct oversize parts.

                    Steve

                    #19578
                    fleetwin
                    Participant

                      US Member - 2 Years

                      A fifty cent hone job is just that! Nothing more than taking a little fine emery to the cylinder walls to rough them up without removing pistons/rings, etc. Simply blow out any left over dust with compressed air/brake clean. No oversize pistons/rings required, just 50 cents worth of emery!

                      #19610
                      1946zephyr
                      Participant
                        quote 20mercman:

                        It idles and runs fine at slow speed, above half throttle, it starts to shake, and any more throttle and shakes so bad that you can’t run it. It has a brand new crank from Chinewalker, +.020 over bore and rebuilt ignition system. I was planning to swap the lower unit to rule that out, just have not gotten around to it. I am afraid I have a balance problem in the powerhead.

                        Steve

                        I would try a different flywheel. If that doesn’t solve it, then the drive shaft and components below it should be checked

                      Viewing 10 posts - 1 through 10 (of 12 total)
                      • You must be logged in to reply to this topic.