User Tag List

Thanks Thanks:  0
Likes Likes:  0
Results 1 to 5 of 5
  1. #1
    Join Date
    Apr 2010
    Location
    VA
    Posts
    5
    Thanks (Given)
    0
    Thanks (Received)
    0
    Likes (Given)
    0
    Likes (Received)
    0
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)

    Question Mercury inline 6 1500 starting problems (newbie)

    I have a mid 70's model Mercury 1500 inline 6. It's always been hard to crank since I've had it but this year it's become worse. The only way I've gotten it to crank is to take the #1 plug out and pour a gas/oil mixture in it. After that it cranks right up and continues to crank until it sits for a few days then I have to do it all over again! Does that sound like a carb or compression problem? Please Help!!

  2. #2
    Join Date
    Aug 2002
    Location
    Kansas City
    Posts
    523
    Thanks (Given)
    0
    Thanks (Received)
    4
    Likes (Given)
    3
    Likes (Received)
    2
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Search the forums; the old inlines are hard to start due to poor choke design. Basically, here is how I start mine:

    - trim the motor all the way in
    - squeeze the primer bulb until firm <slowly>
    - squeeze the primer bulb a few more times until there is an oil slick around the motor
    - push and hold the choke in while cranking

    The fuel pump lacks sufficient capacity to pump while cranking. Squeezing the primer bulb once firm overpowers the carb needles and overflows the carbs. Trimming the motor in causes the excess fuel to flow into the motor from the carbs.

    If you haven't done it already, I would recommend going thru the entire fuel system. The 1500 is not a motor that will survive very long if the fuel system is not in top condition and timing set properly.

    Kirk S.


  3. #3
    Join Date
    Apr 2001
    Location
    Georgia
    Posts
    16,970
    Thanks (Given)
    2
    Thanks (Received)
    35
    Likes (Given)
    45
    Likes (Received)
    169
    Mentioned
    1 Post(s)
    Tagged
    7 Thread(s)
    Kirk's reply covers it all. I might add that I've seen a lot of people PUMP the choke button. Like he said, press and hold until it starts. (fast idle lever up too)

    Squirting gas in the carb would have had the same effect as putting it in a cyl., although in the carb you'd be getting in 2 cyls instead of 1, PLUS it's a lot easier.
    Membership upgrade options: http://www.screamandfly.com/payments.php

  4. #4
    Join Date
    Apr 2010
    Location
    VA
    Posts
    5
    Thanks (Given)
    0
    Thanks (Received)
    0
    Likes (Given)
    0
    Likes (Received)
    0
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Thanks for the help guys. I sunk alot of money in the electrical system last year when i got it(New switch box, wiring harnesses, rectifier, etc). Guess it's the fuel system this year. I already replaced the fuel lines. Should the carbs be re-built? It runs fine once cranked so I think they are good.

  5. #5
    Join Date
    Apr 2001
    Location
    Georgia
    Posts
    16,970
    Thanks (Given)
    2
    Thanks (Received)
    35
    Likes (Given)
    45
    Likes (Received)
    169
    Mentioned
    1 Post(s)
    Tagged
    7 Thread(s)
    I'm thinking it's just technique on starting. Like Kirk mentioned above, the early inlines don't choke worth a crap. There are only two choke butterflies on the top 2 carbs instead of 3. On top of that, they are loose/sloppy and they don't seal well at all. The key to it is flooding gas into the carb throats with the primer bulb with the engine trimmed all the way under. Like Kirk said, you'll see some gas dripping out when you've done it sufficiently. In later years, Merc put a primer system on the inlines that flooded raw fuel into the system, draining from the top carb through a solenoid. The first V6 Mercs in '76 had a metal choke butterfly system in all 6 carb throats that sealed very well, and the EXACT proceedure required of the earlier inlines was no longer necessary. Even so, in later years they also added a solenoid/fuel flood system because some people didn't hold the choke steady until the engine fired, preferring to pump the choke button, which of course hurt instead of helping. Before you spend anymore money, try it that way and see if it doesn't work for you. Fast idle lever up, overpump bulb, hold choke until it fires.
    Membership upgrade options: http://www.screamandfly.com/payments.php

Tags for this Thread

Posting Permissions

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