• If this is your first visit to the iboats.com Boating Forums, be sure to check out the FAQ. To post a question or comment, begin by signing up. To start viewing messages, select the forum that you want to visit from the selection below.


Announcement

Announcement Module
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

What are the symptoms of a bad coil?

Page Title Module
Move Remove Collapse
X
Conversation Detail Module
Collapse
  • Filter
  • Time
  • Show
Clear All
new posts


  • What are the symptoms of a bad coil?

    How will my 70hp Johnson run if I have one bad coil?


  • #2
    Re: What are the symptoms of a bad coil?

    A bad coil can go in and out and cause power surges when you get spark on the dead cylinder. It can just lack power totally because one cylinder is dead from no spark. OR, it can run fine, then when the motor warms up and thermal expansion causes you coil to go out, then lose power.
    I would think that the simple way to find out would be to check spark, then switch coils and see if the spark failure followed the coil. If you have intermittent spark because the coil goes in and out, it's harder to diagnose. Lots of times, you can pull the plugs and see which one is dirty/oily to find out which one isn't getting good spark.
    Good luck,
    JBJ
    Not a certified mechanic but I have at least 2 shade trees in my yard and my wife always says I'm certifiable. So remember that when you follow my advice

    Comment



    • #3
      Re: What are the symptoms of a bad coil?

      I think i have a problem with my coils on my 175hp mercury. it starts first try cold but once it gets warm it wont start for anything. i know its been a long time since this thread has been posted on but if you could, could you give me a update on if you got it to work and what you did? thanks.d

      Comment



      • #4
        Re: What are the symptoms of a bad coil?

        Originally posted by francistran7 View Post
        I think i have a problem with my coils on my 175hp mercury. it starts first try cold but once it gets warm it wont start for anything. i know its been a long time since this thread has been posted on but if you could, could you give me a update on if you got it to work and what you did? thanks.d
        Check out the Mercury section of iBoats:
        http://forums.iboats.com/forumdisplay.php?f=25

        You can check the coils by putting a timing light on the plug wires while running the engine in the same situation you normally experience the problem. Good ones fire steadily and bad ones miss or don't fire at all.

        Comment



        • #5
          Re: What are the symptoms of a bad coil?

          Very old thread to go at again. Suggest you start a new thread stating the issue. Mod's will likely close this one.
          sigpicMarada 2100 Executive Series, 5 Litre V8 with Mercruiser Alpha 1 outdrive. 2007 K-Z Spree 260 RBH, all = a whole lot of family fun !!!!

          Comment

          Working...
          X