Please note this thread has been inactive for 90 days. For the best results, please start a new thread.
Results 1 to 12 of 12
  1. #1
    Seaman Apprentice
    Join Date
    Apr 2010
    Location
    Tennessee
    Posts
    42

    Default 1984 90hp johnson fuel problem

    Driving a boat, it runs good for about a minute, ive rebuilt the carburetors, changed the fuel lines,. The previous owner took the vro off and put a regular fuel pump on it. I thought the fuel pump might be bad, so i took the fuel pump off my 1978 115 hp evinrude and put it on and no change. Im missing something, can someone please help i can push the key in to choke and itpicks up the rpms

  2. #2
    Petty Officer 2nd Class
    Join Date
    Mar 2011
    Location
    TN
    Posts
    144

    Default Re: 1984 90hp johnson fuel problem

    double check float height. Is gas old? Pull the drains out side of carbs and pump primer bulb to make sure flow is good.

  3. #3
    Supreme Mariner Joe Reeves's Avatar
    Join Date
    Feb 2002
    Location
    Central West Florida
    Posts
    10,474

    Default Re: 1984 90hp johnson fuel problem

    Did you manually clean the four (4) high speed jets with a piece of single strand steel wire? If not, do so. Sounds like they're somewhat clogged and you're bypassing them when you push the key in.
    Our Questions Require Answers... If You Refuse To Answer Our Questions... How Can We Answer Yours?

  4. #4
    Seaman Apprentice
    Join Date
    Apr 2010
    Location
    Tennessee
    Posts
    42

    Default Re: 1984 90hp johnson fuel problem

    Yes i cleaned them with wire i will check the float level and while im at it im going to clean the carbs again it can't hurt thanks

  5. #5
    Admiral
    Join Date
    Dec 2005
    Location
    LaGrange, Illinois
    Posts
    7,345

    Default Re: 1984 90hp johnson fuel problem

    Sounds like it is running lean. What happens at full throttle if you constantly prime the fuel hose bulb? Does the rpm pick up?

  6. #6
    Seaman Apprentice
    Join Date
    Apr 2010
    Location
    Tennessee
    Posts
    42

    Default Re: 1984 90hp johnson fuel problem

    It don't make a defferance when pumping the bulb

  7. #7
    Admiral
    Join Date
    Dec 2005
    Location
    LaGrange, Illinois
    Posts
    7,345

    Default Re: 1984 90hp johnson fuel problem

    What changes in the engine after that minute?. Does it shut down, do rpm's drop, what's it doing?

  8. #8
    Seaman Apprentice
    Join Date
    Apr 2010
    Location
    Tennessee
    Posts
    42

    Default Re: 1984 90hp johnson fuel problem

    Drops rpm push key in picks back up

  9. #9
    Supreme Mariner Joe Reeves's Avatar
    Join Date
    Feb 2002
    Location
    Central West Florida
    Posts
    10,474

    Default Re: 1984 90hp johnson fuel problem

    You say "Drops rpm push key in picks back up."

    When you do that, you are injecting fuel directly into the intake manifold, bypassing the carburetors. This indicates that you have overlooked something within the carburetors.
    Our Questions Require Answers... If You Refuse To Answer Our Questions... How Can We Answer Yours?

  10. #10
    Seaman Apprentice
    Join Date
    Apr 2010
    Location
    Tennessee
    Posts
    42

    Default Re: 1984 90hp johnson fuel problem

    I thank i did I'm going to take a half day off tomorrow and take them apart i hope that's what i did

  11. #11
    Seaman Apprentice
    Join Date
    Apr 2010
    Location
    Tennessee
    Posts
    42

    Default Re: 1984 90hp johnson fuel problem

    Finally took it to a shop, left bank power pack was weak, and it had water in the fuel (so i had two issues rather than one). Thank goodness i had an extra parts motor for it. Now i just have to figure out how to get the water out of the fuel, and there is ALOT of water in it. Don't know how it got in there, someone must have put it in there. I think my boy and the neighbor boy did it. But the motor runs great on a separate fuel tank.

  12. #12
    Supreme Mariner Joe Reeves's Avatar
    Join Date
    Feb 2002
    Location
    Central West Florida
    Posts
    10,474

    Default Re: 1984 90hp johnson fuel problem

    Water can be be purchased along with the fuel at any gasoline service station, especially at a marina. Been down that road myself.
    Our Questions Require Answers... If You Refuse To Answer Our Questions... How Can We Answer Yours?

Similar Threads

  1. 1984 Johnson 90hp, Oil injection problem.
    By Nutron in forum Johnson & Evinrude Outboards
    Replies: 1
    Last Post: July 14th, 2011, 11:59 PM
  2. 1984 35hp johnson fuel or electrical Problem Help
    By rshubuck in forum Johnson & Evinrude Outboards
    Replies: 7
    Last Post: November 27th, 2010, 06:00 PM
  3. 1984 90hp Johnson Outboard VRO Problem
    By hasbeenminer in forum Johnson & Evinrude Outboards
    Replies: 2
    Last Post: July 30th, 2009, 11:55 AM
  4. 1984 Johnson 90hp idle problem
    By Rbsgfd578 in forum Johnson & Evinrude Outboards
    Replies: 2
    Last Post: February 23rd, 2006, 01:25 PM
  5. fuel problem? 1984 50HP Johnson
    By jpbramlett in forum Johnson & Evinrude Outboards
    Replies: 5
    Last Post: March 9th, 2004, 03:11 PM
  1. iboats Forum Directory - Over 100,000 forum posts organized by topic