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

89 100hp Mariner compression test

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

  • 89 100hp Mariner compression test

    Going to do a compression check on an 89 100hp Mariner this AM. I understand those are the 2+2 motors and I was wondering if there is anything different about compression checking those as compared to a standard motor. I am not familiar with this system so I was just wondering.

  • #2
    No difference just pull the kill switch lanyard to kill the spark and do the test. The 2+2 system is in controlled by the carbs only the ignition still fires all 4 plugs.

    Comment


    • #3
      Thanks for the reply. What is the thought behind the 2+2 system, is it less fuel and more economical to run or something else?

      Comment


      • #4
        The lower 2 carburetors only allow a wee bit of fuel in at idle.----That is for cooling and lubrication.-------For those who often idle for some time it is a fuel saving idea.

        Comment


        • #5
          Sorry, I keep coming up with questions the more I learn. Is this a system that is still in use or was this kind of a fad thing for a few years and then replaced with something else? Was it dependable or a mechanics (and owners) nightmare? Thanks

          Comment


          • #6
            mechanics (and owners) nightmare!
            1989 Four Winns 170 Cobra 3.0

            Comment


            • #7
              That system was used for close to 15 yrs. It allows for a pretty good idle and saves fuel. I had the 125 version and it is still one of my favorite motors. They are finicky and a factory service manual is a must have. They were only nightmares for people who had no clue how to take care of them or mechanics who were unfamiliar with them.

              Comment


              • #8
                It is a very simple concept !!!---Just not well understood like many outboard concepts !

                Comment


                • #9
                  Where can you find a factory service manual?

                  Comment


                  • #10
                    Originally posted by utfyrfytr View Post
                    Where can you find a factory service manual?
                    A dealer can help you with that.

                    Comment


                    • #11
                      Sign up today
                      or call mercury parts and they will give you a product # when you give them a serial #.
                      https://www.mercurymarine.com/en/us/.../parts-catalog

                      Comment

                      Working...
                      X