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 12 of 12
  1. #1
    Join Date
    Sep 2003
    Location
    New Tripoli, PA, USA!
    Posts
    15,196

    Default "I've had this happen to m

    "I've had this happen to me twice now: Clean carbs, properly set, idling properly, with the recommended jets. Open the throttle in gear and she bogs like crazy--whack it open and she stalls every time. Ease the throttle open and she'll slowly pick up, then go about her business as usual.

    First case was 50 hp carbs on a stock Mark 35A. Latest case is stock carbs on a 650 triple. In the latter case, I have to slap a bit of choke on to get her to rev up in gear--she springs to high revs immediately in neutral, or with my 'test prop' on it (a very low pitch and diameter thingee).

    Anyone know how to cure this nonsense?

    Jeff"

  2. #2
    Join Date
    May 2007
    Location
    Inverary, Ontario, Canada - The Great White North Eh!
    Posts
    9,114

    Default "Jeff, I find sometimes I over

    "Jeff, I find sometimes I overthink things and look for a major problem and it turns out to be something minor.

    It seems safe to assume that you are not getting enough gas. As soon as either motor came under load, it gagged.

    So I'll play the advocate here - see if there was anything common to both motors.

    Were you feeding them with the same gas tank? or fuel line?"
    Graham

    A "professional" is someone who gets paid for their work - it doesn't necessarily mean they are good at it :)

  3. #3
    Join Date
    Sep 2003
    Location
    New Tripoli, PA, USA!
    Posts
    15,196

    Default "Yes and yes. But all my othe

    "Yes and yes. But all my other motors don't do that, so...

    I'm gonna try adding a 1/4 turn richer on the idle settings and see what that does. (What I really need is an accelerator pump, but...)

    Thanks,

    Jeff"

  4. #4
    Join Date
    May 2007
    Location
    Inverary, Ontario, Canada - The Great White North Eh!
    Posts
    9,114

    Default "Have you replaced the gas hos

    "Have you replaced the gas hoses "under the hood" on both of the ones giving you trouble.

    Just re-read your post and see that they were both "more mature" models that would have had gas lines built with rubber compounds used long before the advent of ethanol.

    If original, they may be restricting themselves from the (inside) as the rubber is breaking down or swelling..."
    Graham

    A "professional" is someone who gets paid for their work - it doesn't necessarily mean they are good at it :)

  5. #5
    Join Date
    Sep 2003
    Location
    New Tripoli, PA, USA!
    Posts
    15,196

    Default "All new alcohol-proof stuff.

    "All new alcohol-proof stuff. Good idea, though. Saw some fuel lines on my kit car fall apart after gas-a-hol got to them.

    Jeff"

  6. #6
    Join Date
    May 2007
    Location
    Ireland,the only country in the world you can go North to go South
    Posts
    1,833

    Default "Seeing as I know very little,

    "Seeing as I know very little,but,and this was my experience,when you replaced the fuel lines you didn't by any chance use a smaller bore? Stupid I know,but???? "

  7. #7
    Join Date
    Sep 2003
    Location
    New Tripoli, PA, USA!
    Posts
    15,196

    Default "No. In fact, I use a size lar

    "No. In fact, I use a size larger than normal. And pumping the bulb doesn't seem to help.

    Thanks for the input.

    Jeff"

  8. #8

    Default Another wild theory - couldn&#

    Another wild theory - couldn't be a timing issue? Like not advancing under throttle? Pretty sure that opening the carb butterfly under no load will cause the engine to rev up but not while under load - had that problem on a Suzuki once....

  9. #9
    Join Date
    Jan 2009
    Location
    , Minnesota,
    Posts
    33

    Default Ever get this problem fixed?

    Ever get this problem fixed?

    My motor did something like what you are saying today. Motor ran good got up on plane great than I did a fast idle past some fisherman than punched the motor and it would not wind out. It took prob 2 miles at full throttle than I felt a surge of power and than a little more power and all was good the rest of the day.

    I am thinking a stuck float. My motor is a 1989 200 mariner 3 carb

    Randy

  10. #10
    Join Date
    Sep 2003
    Location
    New Tripoli, PA, USA!
    Posts
    15,196

    Default "Winter has put a halt on my e

    "Winter has put a halt on my experimenting, but not my intent to cure that problem. I'm told adding another 1/4 turn richer on the idle jets might help, but I'm a bit doubtful.

    What I need is someone who knows how to enrichen the mid-range of a Tillotson carb. I'm sure there's a way, and I have a chart showing all kinds of drilled passages on various Merc carbs, so... Another Spring time project.

    On Randy's problem, I'd put my $$ on a fouled plug.

    Jeff"

  11. #11
    Join Date
    Feb 2009
    Location
    perth, wa, Australia
    Posts
    956

    Default Hey Jeff you need to richen up

    Hey Jeff you need to richen up the idle jet 1\4 turn is all you will need and it will cure your problem.

  12. #12
    Join Date
    Sep 2003
    Location
    New Tripoli, PA, USA!
    Posts
    15,196

    Default We'll see! Jeff

    We'll see!

    Jeff

Similar Threads

  1. 1979 OMC 260 carb and/or idle issues
    By floattest in forum OMC Sterndrive and Inboard Forum
    Replies: 23
    Last Post: 09-04-2010, 07:10 PM
  2. 86 Bayliner carb issues??
    By uscgret in forum Volvo Penta Gas Engine Forum
    Replies: 9
    Last Post: 08-10-2010, 02:20 AM
  3. Rochester carb issues
    By sammi in forum Crusader Marine Archive
    Replies: 51
    Last Post: 05-23-2009, 05:27 PM
  4. Yamaha F25 carb issues
    By jeffmoore in forum Yamaha Outboard Archive
    Replies: 7
    Last Post: 08-03-2008, 12:23 AM
  5. Holley carb issues
    By dsums in forum Other Gas Inboard Mfgs IO and Sterndrive Questions
    Replies: 3
    Last Post: 11-25-2006, 09:12 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
  •