Welcome Guest - Sign Up today
Welcome Guest - Sign Up today

Announcement

Collapse
No announcement yet.

1996 Johnson 88 spl low rpm

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

  • 1996 Johnson 88 spl low rpm

    Hey guys I’m new to the forum. I have just recently bought a 2000 17’ polar center console with a 1996 Johnson 88 special on it and when I take it out it is maxing out at full throttle at about 3500 rpm and only reaching around 23 mph. Is this a common problem with these motors? It currently has a 19 pitch prop on it I believe

  • #2
    Hey there!

    It may be something as "simple" as the wrong prop for your application.
    The guru's will know better, but to start with..
    No idea how mechanically inclined you are or are not..

    Sounds like you should first get a baseline health of the engine as it is now...

    Any chance you can run a compression test on it?
    Might be able to rent a compression tester from local auto parts store if you don't have one.

    Also, spark test with an adjustable open air spark gap tester.. Also available at local auto parts store..
    Will spark jump a 7/16" gap on each cylinder?

    Post those results and these guru's will be better able to help you..
    At least they'll be able to say if there are unexpected results, or if you're looking at a prop change or not, etc...

    No better group of knowledgeable minds I've found than right here...

    Going to follow along and see how you make out!
    Hope it helps!
    Current: 1985 17' Jay-Bee Fish/Ski w/1995 Johnson 115hp (J115TLEOR)
    Retired: 1967 15' Cruisers Inc 1532 Camero. Tri-Hull, w/1971 Johnson 50hp (50ESL71) - Possiblity of restoration. (TBD)

    Comment


    • #3
      Agree with checks in post 2. That's a fair bit fo boat and prop for 88HP though - any idea if it ever ran faster?
      '83 Springbok 16' with Franken Xflow, in Southern Alberta. If it ain't smokin', it must be broken.
      Avatar: "Ship Arriving Too Late to Save a Drowning Witch" - Zappa
      My 90-140 engine up-build thread: http://tinyurl.com/hz8uv47


      Comment


      • #4
        Originally posted by jbuote View Post
        Hey there!

        It may be something as "simple" as the wrong prop for your application.
        The guru's will know better, but to start with..
        No idea how mechanically inclined you are or are not..

        Sounds like you should first get a baseline health of the engine as it is now...

        Any chance you can run a compression test on it?
        Might be able to rent a compression tester from local auto parts store if you don't have one.

        Also, spark test with an adjustable open air spark gap tester.. Also available at local auto parts store..
        Will spark jump a 7/16" gap on each cylinder?

        Post those results and these guru's will be better able to help you..
        At least they'll be able to say if there are unexpected results, or if you're looking at a prop change or not, etc...

        No better group of knowledgeable minds I've found than right here...

        Going to follow along and see how you make out!
        Hope it helps!
        Excellent advice. I don't think you're hitting on all four cylinders, unless that boat is REALLY heavy.
        The trouble with doing nothing is that you never know when you're done!

        Comment


        • #5
          So I tested the sparkplugs and one cylinder is not firing good. Haven’t checked compression yet but am gonna try to do that also today

          Comment


          • #6
            My compression was 120,118,112,110

            Comment


            • #7
              Also one side of the motor is hotter than the other side

              Comment


              • #8
                Compression is a little low but consistant, which is good.

                Wear are you seeing the temp difference?

                If on the heads, you may have lost the deflectors in one head. They are under the head covers and look like solid vacuum tube.
                The trouble with doing nothing is that you never know when you're done!

                Comment


                • #9
                  Yes it is the heads. I will have to take them off and have a look.

                  Comment


                  • #10
                    Sign up today
                    Is there a water cooler below the heads where the hose from the heads runs to?

                    Comment

                    Working...
                    X