• 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 Module

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.
See more
See less

Johnson 150 (V6) has oily plugs

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

  • Johnson 150 (V6) has oily plugs

    Hello;I have a 1995 Johnson 150 V6. At startup, the engine smokes alot until warmed up. After a day of running, at least one spark plug is fouled (rpm drops from 5500 to 4800).When I check the plugs, all of them are wet with oil.I took the boat to the local Johnson dealer. They changed plugs and said everything is fine. They also said to be glad it smokes a lot at startup.I have done a compression check, and all cylinders measure between 100 and 110 psi of compression.Can anybody help with why this engine may be over-oiling the fuel.p.s. there are no adjustments (oil, carbs, anything) to make on this engine.Thank you very much.

  • #2
    Re: Johnson 150 (V6) has oily plugs

    They had some carb problems that year that cause a rich mixture problem. This would sometimes cause a flooding problem and would foul a plug. Does the engine seem to be using a lot of oil?


    • #3
      Re: Johnson 150 (V6) has oily plugs

      Hello Fitch;Thanks for your reply on my oily plug problem. The engine does seem to use more oil than I would expect. I would estimate it uses about a gallon of oil for every 40 gallons of gasoline. Also, the two exhaust ports (at the bottom of the powerhead, staddling the flushing port inlet) are the darkest (oily deposits) I've seen on any outboard.Does this still sound like faulty carbs?I sincerely appreciate your help.Ralph


      • #4
        Re: Johnson 150 (V6) has oily plugs

        Another possibility is you have an air leak in the fuel system before the VRO pump, this could cause the Fuel side of the VRO pump to pump faster, this would increase oil consumption.


        • #5
          Re: Johnson 150 (V6) has oily plugs


          • #6
            Re: Johnson 150 (V6) has oily plugs



            • #7
              Re: Johnson 150 (V6) has oily plugs

              Hello;Before purchasing a $225.00 VRO pump, either you or your dealer, should hook a fuel vac***e gauge to this engine. An air leak in the system could cause the problem you describe, but excessive vac***e could as well. If either is present, it will show by hooking up a gauge.The ratio you describe is aprox 32/1 a little rich I'd say!Your problem may well be your pump but make sure before you fork out $225 bucks.Good Luck, Rob


              • #8
                Re: Johnson 150 (V6) has oily plugs

                If you are after a new VRO pump, check out E-bay. In the last 2 weeks they have had 4 from used to new in box. All have sold for under $50 (even the new ones) Could be a cheep way to see if that is the problem.Dave