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Merc Flathead won't stay running..

Discussion in 'The Hokey Ass Message Board' started by Fermiumhalo, Oct 31, 2009.

  1. Fermiumhalo
    Joined: Jul 27, 2007
    Posts: 156

    Fermiumhalo
    Member
    from Japan

    1950 Merc. converted to 12v, MSD dist. I got a new carb on it, it starts up and then starts to idle down... then just shuts off. If you rev it the motor dies after it comes down to idle. Is this a Fuel problem? or spark issue? :mad:
     
  2. strombergs97
    Joined: May 22, 2006
    Posts: 1,888

    strombergs97
    Member
    from California

    Hello..Sounds like your fuel bowl is going empty?? What kind of carb.
    Duane
     
  3. JohnEvans
    Joined: Apr 13, 2008
    Posts: 4,883

    JohnEvans
    Member
    from Phoenix AZ

    Have you tried to adjust the idle mixture screws and idle speed screw??
     
  4. Jim Marlett
    Joined: Aug 12, 2003
    Posts: 867

    Jim Marlett
    Member

    What did it do before the new carb was put on?
     

  5. Fermiumhalo
    Joined: Jul 27, 2007
    Posts: 156

    Fermiumhalo
    Member
    from Japan

    So the carb I had before was the stock teapot with autochoke... I rebuilt it myself, needless to say it would stumble when I got on it. So I ordered the same carb but this one was bench tested and bolt on and ready to run from Mercuryland. Well I put it on and it didn't really wanna run or start. I have plenty of fuel in the bowl. New fuel line no leaks. It will idle for maybe a min and then slowly die. If I gas it a few times it will always die on its way back to idle. I didn't adjust the screws because I was told to not touch it as it was already tuned and touching the idle screws would take it out of calibration. To add to my problems my starter took a NOSE Dive and the spring on the starter broke and now I can't even try running my old carb to see if it idles and runs better then this new one.
     
  6. Fermiumhalo
    Joined: Jul 27, 2007
    Posts: 156

    Fermiumhalo
    Member
    from Japan

    gonna try and get a new spring for the starter, get that fixed and then Install original carb and see if it idles and runs... if so then back to Mercuryland goes this "Ready to Run" overpriced paperweight
     
  7. 31ACoupe
    Joined: Nov 14, 2005
    Posts: 1,416

    31ACoupe
    Member

    you may want to find a ford intake or go aftermarket and switch to holley or stromberg carbs. everyone I know that messed with those teapots came away cussing and disappointed. JMHO.
     
  8. TraderJack
    Joined: Apr 10, 2008
    Posts: 330

    TraderJack
    Member

    Runyur timing light to see if the spark is dying. If not, it is fuel. Check for fuel pressure, or a clogged filter or gas line.


    traderjack
     
  9. Fermiumhalo
    Joined: Jul 27, 2007
    Posts: 156

    Fermiumhalo
    Member
    from Japan

    TraderJack good idea! So can it be too much Fuel? flooding out... cause I'll rev it and it will die on the way back to idle almost like its flooding. I'm on my way to get a starter so I can replace the spring on mine and tackle this by the horns!
     
  10. What fuel pump are you using? Is it as simple as an idle screw adjustment?
     
  11. oldschool59
    Joined: Jan 3, 2008
    Posts: 51

    oldschool59
    Member

    My first post. Set your idle mixture,sounds to lean, There is no way to set a carb up on the bench to work on all motors in all conditions.The outside world is to full of variables.Set it up by "ear" if you have experience or "vacuum gauge" or find a buddy.I would love to help but you are a few miles and 1 country away.Good luck.Oh by the by,the advice comes from 25 yrs on the tools as my livin and 35 yrs messin with motors,for what it's worth.

    Regards
    Mike
     
  12. Fermiumhalo
    Joined: Jul 27, 2007
    Posts: 156

    Fermiumhalo
    Member
    from Japan

    Mike thanks for the help! I just drove to this guys house and picked up a starter. About to remove the spring and put it on mine. Then I will put the old carb on and see what happens. The fuel pump is a mechanical one. Look forward to a update in a few hours! Thanks everyone for the help! I need to get this thing running before I return to Japan, or else I'm gonna be one upset cookie!
     
  13. 32ratsass
    Joined: Dec 14, 2007
    Posts: 258

    32ratsass
    Member

    I'm going along with oldschool59 on this one, as I've never seen a carb "bench set" that would run well with no adjustment on the engine. Sounds like idle mix/idle speed to me. Between the two of us, that's 50 years, and 80 years.:)
     
  14. Fermiumhalo
    Joined: Jul 27, 2007
    Posts: 156

    Fermiumhalo
    Member
    from Japan

    okay guys thanks again for all your help. yesterday I got the new spring installed on the starter, I put back original carb and she started right up:) idled and ran. Then another issue!!! can you believe my luck :( my fuse link popped. So now I'm at a loss for words. I had a 30 amp fuse in line on the wire from starter button to solenoid as the orignal wiring harness' fusable link burned up. It only pops the fuse when you rev the motor as you rev the motor it pops. It was running fine on the 30 amp fuse before. Do I need a bigger fuse?
     
  15. Fermiumhalo
    Joined: Jul 27, 2007
    Posts: 156

    Fermiumhalo
    Member
    from Japan

  16. Fermiumhalo
    Joined: Jul 27, 2007
    Posts: 156

    Fermiumhalo
    Member
    from Japan

  17. Petejoe
    Joined: Nov 27, 2002
    Posts: 11,094

    Petejoe
    ALLIANCE MEMBER
    from Zoar, Ohio

    First..
    Be SURE you have good grounds. 3 of them.
    00 welding wire size. Cab to frame.. frame to engine and engine to cab.
    Check all your connections and wires at the solenoid and starter.
    There are two types of starter circuits.
    Some starter buttons are designed to ground out the solenoid to get it to operate.
    Others are actually carrying the positive 12 volts to operate it.
    If its the latter be sure the button to solenoid wire is not grounding somewhere.
    Do not increase the fuse size.
     
  18. Fermiumhalo
    Joined: Jul 27, 2007
    Posts: 156

    Fermiumhalo
    Member
    from Japan

    Petejoe Thanks for the advice, I'm gonna check the wiring today, whats crazy is that the car will start with a 15amp fuse. Idle forever and the min you gas it a few times "POP" Which then cuts power to the whole car, I'm guessing that wire is what carries power to the Fusebox.
     
  19. JohnEvans
    Joined: Apr 13, 2008
    Posts: 4,883

    JohnEvans
    Member
    from Phoenix AZ

    You got a Gen or Alt? If that fuse is in the output of the Alt/Gen to the battery it WILL blow when you rev it up if the battery is the least bit low. A fuse and a fuseable link are NOT the same thing . You will need a 50-60 amp fuse there if you are running a Alt. , better a piece of 14 Ga true fuseable link wire. Even back in Gen. days when they had a fuse mounted on the volt reg they were 40-50 amp rated.
     
  20. Fermiumhalo
    Joined: Jul 27, 2007
    Posts: 156

    Fermiumhalo
    Member
    from Japan

    JohnEvans: I have a ALT. I converted the car to 12volt, new wiring harness, and so I used an alternator.. Originally where that fuse holder was there was a 14Ga fuseable link. It smoked and burned up and thats why I installed a inline fuse holder. So could it be that the alternator that I'm running is pushing too many Amps? I can't find a short anywhere. It only blows when you rev the motor and the 30 amp lasted till last night. Wonder if I should install another 30amp or go higher. Recommendations?
     
  21. Fermiumhalo
    Joined: Jul 27, 2007
    Posts: 156

    Fermiumhalo
    Member
    from Japan

    I just realized that while tackling that carb issue, I drained the battery! So JohnEvans you are right on the money with the battery being low and causing the fuse to blow!
     
  22. Stafford
    Joined: Feb 15, 2005
    Posts: 109

    Stafford
    Member
    from N. Georgia

    I'd say it's a fuel delivery problem. has the car been setting a long time? You might wanna try blowing back thru the gas line to the tank. Take the gas line loose from the carb and spin it over and see if it's pumping good. catch it in a jar so you don't start a big fire. The flatheads are pretty simple motors. I did see a chevy small black act like that once and the wires to the coil were crossed, but it would start and go dead real quick. my brother had a 40 ford that would do what yours is doing and the tank had a rats nest in it and it kept stopping up the fuel line. to compound his problem the cam where the fuel pump pushrod ran had a groove wore in it and it renderd his mechanical pump useless. ended up with an electric pump and it cured his problems along with the MSD distributor. I changed mine to 12 volts also and kept on breaking springs on the starter. I'm gonna get one of the gear reduction starters and do away with that damned spring
     
  23. 32ratsass
    Joined: Dec 14, 2007
    Posts: 258

    32ratsass
    Member

    Sorry to sound so dense, but if I'm reading correctly, you stated that the fuse was in the line from the starter button, to the solenoid.:confused: If that's the case, the only time there is power on that line is when you push the button. After it's started, reving it up wouldn't make any difference, as that line has no power on it. The rest of the explanations, and thoughts sound right on the money, just not on that line.:) (Looking at your pics, it looks like the big red line with the fuse holder is the charge line from the alternator, or the main electrical supply to the fuse box. The purple wire looks like the starter button to solenoid.) Being confused:confused: makes me crazy. Please straighten me out here!!!!
     
    Last edited: Nov 2, 2009
  24. UnIOnViLLEHauNT
    Joined: Jun 22, 2004
    Posts: 4,824

    UnIOnViLLEHauNT
    Member

    E dog, I called you earlier but didn't get an answer. Did you figure this out? I just came in now and am bout to make some dinner, ring me up if ya want.
     
  25. JohnEvans
    Joined: Apr 13, 2008
    Posts: 4,883

    JohnEvans
    Member
    from Phoenix AZ

    You need to know what the output of the Alt is to properly size a fuse/fuseable link . Fuseable links are a bit like slow-blow fuses ,will take a bit of overload for a short time. I would try a 12 Ga fuseable link if you blew a 14 Ga one. The regular fuse is not a good thing to use for this app., taking full output of the Alt. through it.
     
  26. Fermiumhalo
    Joined: Jul 27, 2007
    Posts: 156

    Fermiumhalo
    Member
    from Japan

    32 Your right the wire in question here is the supply from the alt. JohnEvans got it right on the money! The fuseablelink that came on the harness was burned out probably from the fact the Alt. Is putting too much for it to handle, I'm gonna try and see how many amps this Alt is pushing and then remove the INLINE 30amp fuse and solder in a 12gauge wire like suggested. I just drove the car about 20 mile round trip and it ran great no issues, this is after recharging the battery and a new 30amp fuse installed... Thanks again for Everyone's help!! Much Much appreciated !
     

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