Welcome Guest - Sign Up today
Welcome Guest - Sign Up today
Store Links Mobile - Shop Now

Announcement

Collapse

Help Tip: If you have a question that has not been answered to your satisfaction in the archives, it is always best to start a new thread of your own. By starting your own thread, you will receive the maximum number of views by forum members.

Below are some additional forum policies in hopes of all iboats members will follow, Thank you.

1. Please do not reply to old topics or hijack existing topics. Old topics of a technical nature are like a library book, Please do not write in them.

2. Old topics should be considered archives and used for reference only. Please do not reply to them.

3. Do not take over someone elseís topic (aka hijack) with your own question, even if it is similar. If you have a question that has not been covered to your satisfaction in the archives, it is always best to start a new topic of your own.

4. If you have a question for the original poster (OP) and the topic is over 30 days old, send the OP a PM, he may not even visit the forums any longer, or may not notice your question in the old topic.

5. By starting your own topic, you will receive the maximum number of views by forum helpers that may not even notice your question when itís posted at the end of someone elseís topic. And those answers will be specific to your particular issue.

6. Please do not post to topics that have been inactive for more than 3 months unless you are the original poster. We have very active forums and any topic that remains inactive for that long should be considered "dead". It is especially confusing when there is an entirely new question posted to an old topic.

7. Posting at the end of any topic is considered to be hijacking the original posters topic which in turn subjects the topic to be closed if it continues to happen thus not making it fair to the original poster in the future had for some reason he/she needed to return for additional information or provide an update of the problem solved which is always welcomed within a reasonable amount of time frame.

8. Please note that you should see a red banner pop up near the bottom of each inactive topic asking you not to reply to old topics. The Red banner will read: Please note this topic has been inactive for 90 days. For the best results, please start a new topic.

Thank you all in advance for doing your part in helping iboats run a smooth ship.

Additional forum rules linked below.
http://forums.iboats.com/forum-rules-guidelines-405/
See more
See less

OMC Gearcase Questions

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

  • OMC Gearcase Questions

    Boat title says it is a 1978 Mark Twain. On the gearcase it just says OMC Sterndrive (no 400 or 800) with a 235hp on a sticker below that. According to the Clymer's Shop Manual that I have, the 235hp set up was for 1977 models. Tag on the gearcase says Model# 983489 - Serial# J351978. So does this make it a Electromatic gearcase? The change happened between 77 & 78 so I want to make sure. If so can I use Lucas 80-90W high performance gear oil?

  • #2
    I think '77 was the last year for the 235HP. But the model number would be on the engine tag - typically on the starboard side somewhere around the rear motor mount. The number should read something similar to 990240E 1977.

    Yes, yours would be an electric shift. Lower gear case needs to be Type C lube. Upper gear case can be any that you like. The lower needs a thinner lube otherwise the shifting doesn't work quite right.
    [ATTACH=CONFIG]temp_270443_1499813187632_202[/ATTACH]

    Comment


    • #3
      Take a picture of your drive and post it.
      1998 Wellcraft Eclipse 24 Cuddy
      Volvo Penta Duo-Prop 7.4L "LK"

      2006 Sun Tracker Party Barge 21
      Mercury 90 4-Stroke FI
      "Common sense is not very common"
      "Failing to prepare is preparing to fail." -- John Wooden

      Comment


      • #4
        throw the clymer manual away (they are filled with incorrect information and are best used as knee pads) get a factory manual

        most boat manufacturers used motor/drive combinations until they ran out of stock. this may be 2 or 3 years after OMG stopped producing

        1988 Cruisers Rogue 2420 -VP 290 DP now powered by custom 468 - http://forums.iboats.com/forum/owner...988-rogue-2420

        Past Boats
        1970 Wooster Hellion - Merc 9.8
        2002 SeaRay 190BR - 5.0 - A1G2 - "Cheasheads in Paradise"
        1984 Avanti 170DLI -3.0 stringer- "Ship Happens"

        What’s behind you doesn’t matter.Enzo Ferrari

        Comment


        • #5
          Originally posted by southkogs View Post
          I think '77 was the last year for the 235HP. But the model number would be on the engine tag - typically on the starboard side somewhere around the rear motor mount. The number should read something similar to 990240E 1977.

          Yes, yours would be an electric shift. Lower gear case needs to be Type C lube. Upper gear case can be any that you like. The lower needs a thinner lube otherwise the shifting doesn't work quite right.
          990241G is what I have pulled from something.

          Comment


          • #6
            Originally posted by Scott Danforth View Post
            throw the clymer manual away (they are filled with incorrect information and are best used as knee pads) get a factory manual

            most boat manufacturers used motor/drive combinations until they ran out of stock. this may be 2 or 3 years after OMG stopped producing
            Where does one find a factory manual for this old girl?

            Comment


            • #7
              the manuals are ordered thru ken cook company (original publisher for OMC) or you find a used on on ebay.

              https://www.outboardbooks.com/brand/OMC/

              There are 4 lists for 1977 235hp, all of them have the same manuals listed

              https://www.outboardbooks.com/manual/990241G/OMC/
              https://www.outboardbooks.com/manual/990240E/OMC/
              https://www.outboardbooks.com/manual/990240G/OMC/
              https://www.outboardbooks.com/manual/990241E/OMC/
              1988 Cruisers Rogue 2420 -VP 290 DP now powered by custom 468 - http://forums.iboats.com/forum/owner...988-rogue-2420

              Past Boats
              1970 Wooster Hellion - Merc 9.8
              2002 SeaRay 190BR - 5.0 - A1G2 - "Cheasheads in Paradise"
              1984 Avanti 170DLI -3.0 stringer- "Ship Happens"

              What’s behind you doesn’t matter.Enzo Ferrari

              Comment


              • #8
                Originally posted by Twainer View Post
                990241G is what I have pulled from something.
                That's it. 1977 235HP Electric Shift with Select trim.
                [ATTACH=CONFIG]temp_270443_1499813187632_202[/ATTACH]

                Comment


                • #9
                  Sign up today
                  Originally posted by Scott Danforth View Post
                  the manuals are ordered thru ken cook company (original publisher for OMC) or you find a used on on ebay.

                  https://www.outboardbooks.com/brand/OMC/

                  There are 4 lists for 1977 235hp, all of them have the same manuals listed

                  https://www.outboardbooks.com/manual/990241G/OMC/
                  https://www.outboardbooks.com/manual/990240E/OMC/
                  https://www.outboardbooks.com/manual/990240G/OMC/
                  https://www.outboardbooks.com/manual/990241E/OMC/
                  Thanks for the link.

                  Comment

                  Working...
                  X