6hp Techumseh won't idle

Discussion in 'Mechanic and Repair' started by smokediver, Nov 24, 2007.

  1. smokediver

    smokediver LawnSite Member
    Posts: 59

    I know there's no fuel coming through the idle circuit, but I don't know why. I've encountered this problem before and never got to the bottom of it. I've removed and thoroughly cleaned the carb. Even removed the side cover and checked all the little holes that dump out right by the throttle plate, and the passage back to the main jet tube. Sprayed carb cleaner through all of them, but there's no fuel for idle. I set the governor up to blip the throttle before it dies, and it will run by surging up and down with the throttle blips, but no smooth idle.
    What makes this particular model not draw fuel for idle? It's driving me nuts!! It's the carb with the plastic main jet and "o" rings. I replaced them last time but it didn't help. It runs smoother with the primer bulb held in, but I think it drafts fuel through the priming hole in the intake side of the carb. Covered the primer bulb with plastic wrap to check for holes, no good. WHAT IS IT that keeps fuel from flowing through that idle circuit??!!?? HELP!!!
     
  2. Restrorob

    Restrorob LawnSite Fanatic
    Posts: 11,022

    Post the model AND spec. numbers off this engine....
     
  3. smokediver

    smokediver LawnSite Member
    Posts: 59

    Model: OHH60
    Spec : 71131E
     
  4. Grass Happens

    Grass Happens LawnSite Senior Member
    Posts: 682

    Um, does it say vector on it? If its what i think it is, the one with the plastic carb and what not, good luck! they are junk.
     
  5. Restrorob

    Restrorob LawnSite Fanatic
    Posts: 11,022

    Did you dig the plastic cap ref. #20A out and remove ref. #20 low speed jet ?

    There is a small hole in the end of this jet, A bristle from a hand wire brush works well for opening this hole, Spray your carb cleaner through this port then re-install the jet.



    [​IMG]


    If you have already done this then it may be time for a new carb;

    http://search.cartserver.com/search/search.cgi?cartid=a-8671&category=Tecumseh_Parts&maxhits=20&keywords=640025C&go=GO%21

    I no longer monkey with carbs that parts and labor exceed the price of a new one, I just install a new one and bypass all the crap like your having....

    Good Luck
     
  6. topsites

    topsites LawnSite Fanatic
    Posts: 21,653

    You did replace the inline and the in-tank fuel filters, yes?

    If it's not that then it's a Tecumseh, that's likely the problem.
    It's just like that with cheap engines, they run great for some time then it's problems.
    I know, I've done far more to keep one running, pretty much replaced everything except the engine itself, even put a new cylinder head gasket on it... It runs better but it still has the same problem, it's about to that point, in my case if a new engine were not almost as much as the machine itself I would replace it, but now I'm just running it until I can afford a whole new machine.

    Depending on the machine and how much life is left in it, if you're guessing little to none then trash it.
    A few to several years I'd consider a briggs, if it's got a lot of life left in it then get something like a Kohler / Kawasaki / Honda.
     
  7. smokediver

    smokediver LawnSite Member
    Posts: 59

    Yes, I did remove and check the low speed jet, and flushed all openings. I even removed the high speed jet (plastic tube) and confirmed that the passsage from there to the low speed jet was clear.
    I have not changed any filters since the bowl is full of fuel, and flows steadily from the fuel line.
    I've theorized it must have something to do with that little plastic tube and the "o" rings. Best I can figure that tube is supposed to be sealed at both ends so fuel weeps in through the small notch in the bottom and then is drawn out through the low speed circuit. If the top isn't sealed it would suck air fron the throat of the carb and not draw fuel, wouldn't it?
    If the fuel level was low, like the float was out of adjustment, would it be unable to draw fuel?
    I've got 2 others that run perfectly, but this is the 2nd one to have this problem. It seems to follow a long period of non use, like about a year.
    It's gotta be something simple. There's not that much to the thing?? And the price I got for a new one was like $70!
    Any other ideas guys?
    Thanks for all your help....
     
  8. DEEREBOY14

    DEEREBOY14 LawnSite Member
    Posts: 69

    look briggs&stratton r honda
     
  9. Restrorob

    Restrorob LawnSite Fanatic
    Posts: 11,022

    Gander at this;

    http://images.search.yahoo.com/sear...jpeg&no=4&tt=74&oid=128a189d44ee0d14&ei=UTF-8


    Scroll down to the eighth picture and read the caption above it, He speaks of the extra passage going up the side of the main jet holder. This passage is NOT cleanable, There is NO way to get to it for cleaning. In the past I left one of these carbs in a bucket of carb cleaner for 3 weeks and it still wouldn't run right.

    That's why I replace them rather than waste time on them.
     
  10. smokediver

    smokediver LawnSite Member
    Posts: 59

    :laugh: Well, that clears things up a little.

    That extra little hole in the side of the main jet was clogged. I never knew that one was there. I'll have to check the rest of the passage later. Where there's a will, there's a way.

    Any magic tricks on how to remove those little "BB" plugs?

    Thanks for the info.....
     

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