briggs help

Discussion in 'Mechanic and Repair' started by keifer, Jan 13, 2002.

  1. keifer

    keifer LawnSite Senior Member
    Posts: 320

    I have a little 4 horse vert shaft that wont start unless I put my thumb over the carb then it will run for a minute. it will stay runing if i put my thumb over the carb then take it off then put it back over. I cleaned the carb but still didnt help? any advice would be of great help. Thanks
     
  2. CPLLTT

    CPLLTT LawnSite Member
    from Oregon
    Posts: 17

    You have a plug in the fuel system somewhere. Holding your thumb over the carb intake acts as a choke to draw more fuel into the engine. Check your float needle inlet carefully for junk, then try (carefully) blowing air thru the fuel line from where it attaches to the carb so it blows into the tank. You will then probably need to drain and clean the gas tank.
     
  3. vipermanz

    vipermanz LawnSite Bronze Member
    Posts: 1,773

    alrighty, i just did the same thing to mine,
    1. remove air cleaner and filter frame.
    2.Take off gas tank, one bolt is to the left of the primer adjacent to the gas cap, the others go across the front of the engine, (4) total. DO Not Remove Tank Yet!
    3.take a good look at the carbs linkages there should be 2 springs.
    4. Carefully un-hook the springs off of the air vane shaft.
    5. Remove the tank and carb assembly by pulling out with a slight clockwise motion (it joins the intake pipe by compression).
    6 The carb. has 5 screws on the top side, remove screws and place in a steady location these are special order screws!.
    7.Once screws on carb are removed, Gently pull up on the carb not damaging the Diaphragm in any way!.
    8. Once carb and tank are separated there should be 2 holes, the one on the left is fuel intake , the right side hole is the fuel bowl, take a flashlight and look in the right side fuel bowl for trash.
    9.on the fuel pipe that goes into the gas tank, there is a screen, remove and clean with spray of carb cleaner or compressed air.
    10. once carb is free of all trash begin to re-assemble.
    11.Tighten all carb screws Securily.
    12.install tank and carb to intake pipe, make sure there are 2 washers in the throat of the carb where it meets the intake pipe, these are soft o-rings.
    13.Once tank is re-mounted , connect the carb linkages Exactly the way they were before!.
    14.Reinstall air filter assembly.
    15.Put fresh gas in the tank.
    16.Because the fuel pipes and bowl are emtpy , it will take a Large amount of primes to fill it back (ie.15)
    17.Try out your luck!
     
  4. keifer

    keifer LawnSite Senior Member
    Posts: 320

    Thanks alpine and viper. I cleaned the carb once but must have missed somthing ILL try agine with a new gass line and maybe a fuel filter. viper its a 95 model. I think the older ones and mostly the 3 1/2 horse ones had the type carbs you described.



    Thanks agine.

    PS. hey viper / roll tide.
     
  5. vipermanz

    vipermanz LawnSite Bronze Member
    Posts: 1,773

    ah crap , you said it's a vertical. i have a 4hp horizontal , opps!

    War Eagle sounds better:D
     
  6. BRIAN GALLO

    BRIAN GALLO LawnSite Senior Member
    Posts: 282

    Check and clean your carb main jet real good. It sounds like a definate fuel starvation problem. You might also want to check the float adjustment and needle valve.
     
  7. LAZERMAN

    LAZERMAN LawnSite Member
    Posts: 19

    KEIFER FIRST THINGS FIRST ARE YOU GETTING FUEL TO THE CARB? IF SO TAKE CARB OFF AND CLEAN IT WITH A GOOD CARB CLEANER AND BLOW IT OUT WITH AN AIR LINE. WHEN YOU GO TO PUT IT BACK TOGETHER LOOH AND THE SCREW THAT HOLD THE BOWL ON, THATS THE MAIN JET. TAKE A PIECE OF WIRE OR JET CLEANERS AND CLEAN THE HOLES OUT, PUT THE SCREW AND WASHER BACK IN AND REATTACH THE CARB AND YOU SHOULD BE READY TO GO. IF THIS STILL DOESN'T WORK WRITE BACK AND LET US KNOW.



    LAZERMAN
     
  8. keifer

    keifer LawnSite Senior Member
    Posts: 320

    Hey guys I cleaned the carb once more and she is running. went to ajust it and it didnt even have mixture screw or a place for one? Viper I was at walmart and seen a 4 horse with the carb as you described my bad i thought they stoped makin those. oh well the old lady will be happy that she has her own mower for the garden. ps I put some high back wheels on it she looks pretty snazzy.
     
  9. jason2

    jason2 LawnSite Member
    Posts: 243

    I wouldn't use a wire to clean a jet. If you do, be very careful, you can mess up the jet. I'd stick to using compressed air.
     
  10. Robert Doubrava

    Robert Doubrava LawnSite Senior Member
    Posts: 342

    Recently, I cleaned the jet on my 7HP, and what I do to clean it, is get some carburator cleaner, and line the hole of the red spray tube with the end of the jet and squirt it and see if any fluid comes out ALL of the holes. That's also a good way to see if the holes are blocked.:) Just be careful not to aim it near your eyes. I got some in mine a few times.:( It burns like heck.
     

Share This Page