Logo
Get instant online access to repair manuals for your Mercury / Mariner outboard. Online Manuals
MercuryMariner
Order printed Mercury / Mariner service manuals — shipped to your door! Printed Manuals
MercuryMariner
Use engine diagrams to find & order parts for your Mercury / Mariner engine. Engine Diagrams
MercuryMariner
Find parts quickly with Mercury application guides. Quick Parts Guide
MercurySierraCDI
Results 1 to 4 of 4
  1. #1

    Default 2003 merc 40hp 4strok wont run right after running then restarting

    We have a2003 40hp murcury 4stroke on our pontoon boat it has started giving us fitz we will run it for a while /15 min to 45 min/ then we will shut it down for /5min to 20 min/when restarting it will run terrible sounds like maybe on one cyl stalling and very little power then after 10 min or more of restarting it will up and run sometimes. Other times we need to dock it and go back 1 or 2 hrs later and it will run great again .I change fuel filters and plugs and drain replace gas every year motor pees like a 10 year old . Any help on this would be great

  2. #2
    Join Date
    Apr 2016
    Location
    barnegat NJ
    Posts
    3,143

    Default Re: 2003 merc 40hp 4strok wont run right after running then restarting

    Try a cylinder drop test at idle, pull one spark plug wire one at a time,listen for sound and rpm change. a timing light could verify plugs are getting spark, If there is no rpm change on a cylinder, There's your culprit

  3. #3

    Default Re: 2003 merc 40hp 4strok wont run right after running then restarting

    what would make this happen in this manner could it be the coil on the cyl that drops or somthing else

  4. #4
    Join Date
    Sep 2003
    Location
    New Tripoli, PA, USA!
    Posts
    15,691

    Default Re: 2003 merc 40hp 4strok wont run right after running then restarting

    find out if it's loosing ignition first.

    jeff

Similar Threads

  1. Mercury 2003 2 stroke not restarting
    By Toby1 in forum Mercury Mariner Outboard Forum
    Replies: 1
    Last Post: 06-24-2018, 12:00 AM
  2. 5hp Merc wont stay running. Gas?
    By Akempf79 in forum Mercury Mariner Outboard Forum
    Replies: 1
    Last Post: 04-21-2014, 09:13 PM
  3. 1976 40hp Evinrude wont stay running
    By 62SeaKing in forum Johnson Evinrude Outboard Forum
    Replies: 9
    Last Post: 06-21-2010, 11:56 PM
  4. 2003 225 hp BF225 wont stay running
    By get1on in forum Honda Outboard Forum
    Replies: 9
    Last Post: 04-16-2010, 07:36 AM
  5. Restarting after initial running 90Hp 200 yearmodel
    By arky in forum Johnson Evinrude Outboard Archive
    Replies: 0
    Last Post: 07-26-2009, 05:26 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •