Please note this thread has been inactive for 90 days. For the best results, please start a new thread.
Results 1 to 2 of 2
  1. #1

    Default Setting the Timing on a 1978 Mercruiser MCM 140

    I rebuilt a 1978 Mercruiser MCM 140 and got great help from this site. I am all done, it runs great, but I want to set the timing so it's perfect and I can enjoy it without worrying about it. Ignition timing is supposed to set at 6 degrees BTDC. I can't find the line I'm supposed to see (lots of scratches & such). If I take the distributor cap off and turn it to position 1 will that make it easier to find? Can someone give me the steps on how to set the timing right, after I find the mark? I do have access to a timing light. Thanks for your help.

  2. #2
    Moderator Bob_VT's Avatar
    Join Date
    May 2001
    Location
    West Rutland, Vermont, United States
    Posts
    24,368

    Default Re: Setting the Timing on a 1978 Mercruiser MCM 140

    Take out plug #1 and turn engine until #1 is at TDC on the compression stroke. Your rotor should be pointing towards the #1 wire on the distributor cap. Now look around for your timing mark. Use a piece of emery cloth to sand around lighly and the mark should appear. Paint the mark with paint or white-out correction fluid (LOL No one uses it anymore).Time to your hearts content.Bob
    This is a great link to boat specifications http://boatspecs.iboats.com/
    Please, shop iboats first!!


Similar Threads

  1. Ignition Timing Setting on 1989 4.3 V6 Mercruiser
    By dvd6503 in forum Mercruiser I/O & Inboard Engines & Outdrives
    Replies: 7
    Last Post: May 10th, 2010, 12:16 PM
  2. Setting the ignition timing on a Mercruiser 4.3 EFI
    By SandyBoat in forum Mercruiser I/O & Inboard Engines & Outdrives
    Replies: 9
    Last Post: January 23rd, 2009, 06:58 PM
  3. Mercruiser 4.3 Setting base timing.
    By JoeDemaree in forum Mercruiser I/O & Inboard Engines & Outdrives
    Replies: 3
    Last Post: July 2nd, 2007, 01:29 PM
  4. 1991 Mercruiser 4.3L V6 Timing Setting?
    By mmadlener in forum Mercruiser I/O & Inboard Engines & Outdrives
    Replies: 3
    Last Post: May 9th, 2004, 07:40 AM
  5. Setting the distributor? timing on a 3.0L Mercruiser
    By jayschaum in forum Mercruiser I/O & Inboard Engines & Outdrives
    Replies: 0
    Last Post: July 30th, 2002, 01:38 PM
  1. iboats Forum Directory - Over 100,000 forum posts organized by topic