Please note this thread has been inactive for 90 days. For the best results, please start a new thread.
Results 1 to 3 of 3
  1. #1

    Default How do I tune my MerCarb?

    I have a 1989 Thompson with a 4 cyl. 2bbl. Mercarb. I have had trouble with the engine flooding (gas runs down venturi after engine is stopped, leaves about 1/4" in bottom of intake manifold). I have read some of the postings and am going to check on the float setting, and rebuild the carb while I'm at it. Does anyone know how to tune in the carb when I'm done. There is only one idle screw, but I've never adjusted one before. Any suggestions would be appreciated.

  2. #2
    Captain
    Join Date
    Nov 2001
    Location
    Southern Alabama
    Posts
    3,333

    Default Re: How do I tune my MerCarb?

    You need to rebuild the carb for shure! But you also will need to know which Mercarb you have. Look at this link and measure. The idle adjustment is really easy. Warm engine and then adjust the screw both ways (about 1.5 turns from in) till it idles smooth. Too much either way will (shake). Carb

  3. #3

    Default Re: How do I tune my MerCarb?

    Thanks,I rebuilt the carb and it runs sweet now. Now I have another post for my stern drive.

Similar Threads

  1. Mercarb Help
    By rlambert in forum Mercruiser I/O & Inboard Engines & Outdrives
    Replies: 8
    Last Post: May 6th, 2010, 11:05 AM
  2. Converting Mercarb 2bbl (5.7L) to Mercarb (3.7L)
    By natemoore in forum Mercruiser I/O & Inboard Engines & Outdrives
    Replies: 2
    Last Post: November 2nd, 2009, 08:00 PM
  3. new mercarb
    By blazer in forum Mercruiser I/O & Inboard Engines & Outdrives
    Replies: 5
    Last Post: April 18th, 2007, 02:02 PM
  4. What paint for a Mercarb?
    By wake5150 in forum Mercruiser I/O & Inboard Engines & Outdrives
    Replies: 3
    Last Post: April 8th, 2005, 06:22 AM
  5. Mercarb Bog
    By cg2er410 in forum Mercruiser I/O & Inboard Engines & Outdrives
    Replies: 2
    Last Post: August 20th, 2004, 12:07 PM
  1. iboats Forum Directory - Over 100,000 forum posts organized by topic