Craftsman mower no start

Discussion in 'Mechanic and Repair' started by fireman649, Aug 3, 2006.

  1. fireman649

    fireman649 LawnSite Member
    Posts: 76

    Craftsman push mower with a 6.5 hp Briggs. I can't seem to get this thing started. When you push the primer bulb on the front which acts as the choke, you don't feel or hear any fuel moving. It's not priming. I already replaced the carb, because someone else blew the seat and another part out with compressed air. Has anyone else seen this problem, If I could get it to prime, it would be fine.
    Thanks in advance

    Steve
     
  2. dutch1

    dutch1 LawnSite Silver Member
    from Jayhawk
    Posts: 2,231

    There is no need to replace the carb juat because the seat was blown out during clean up. If it is the typical briggs, rebuild kit is #498260 and it will also contain an air horn gasket which I suspect you possibly have lost in the process. Since you say the unit will not prime, the gasket is likely missing or the primer bulb possibly has a split. You gave no engine numbers so this is the best I can suggest at the time.

    Dutch
     
  3. fireman649

    fireman649 LawnSite Member
    Posts: 76

    I got a new carb and primer assembly from ebay that came off a running engine. I took the primer bulb off, there are no splits. Why would it be doing it to 2 different primer bulbs, there must be something else going on. I will post engine number tommorrow, I'm on duty today.
     
  4. dutch1

    dutch1 LawnSite Silver Member
    from Jayhawk
    Posts: 2,231

    If the gasket between the air filter base and the carb is missing the primer will not force fuel out of the carb bowl into the venturi of the carb. You did not mention whether the gasket was there or not.

    Dutch
     
  5. Restrorob

    Restrorob LawnSite Fanatic
    Posts: 11,022


    Ditto, Even trying to reuse this gasket could lead to a non-working condition.
     
  6. fireman649

    fireman649 LawnSite Member
    Posts: 76


    The gasket is there and it is good.
    Thanks
     
  7. dutch1

    dutch1 LawnSite Silver Member
    from Jayhawk
    Posts: 2,231

    You might check to see if there is an obstruction in the primer port between the primer and where it exits the filter base. Manually prime the unit with the filter base off, then likely the problem lies in the priming circuit, either a blockage as I described, a crack in the air passage or an insufficient seal in the primer bulb.

    In the years I spent in a shop envoirnment I saw an obstruction in the primer port a couple of times.


    Dutch
     
  8. Restrorob

    Restrorob LawnSite Fanatic
    Posts: 11,022


    This gasket can look good and still not seal the primer circuit, This has been a on going problem with these plastic air filter base's. REPLACE the gasket and start the screws in the base, Before they tighten completely apply a small amount of downward pressure on the top of the base and ONLY snug the screws. Over tightening this base could cause warpage and air leak and non primer operation.
    If it still does not function you can try installing 2 gaskets, If still no go it's time to replace the base assembly. The plastic warps from heat over time and causes a no seal situation.
     
  9. newz7151

    newz7151 LawnSite Silver Member
    from Tejas
    Posts: 2,419

    Upward pressure from the bottom so that you can be sure the bottom "lip or edge" of the air track on the AC base will be all the way up on the carburetor face.
     
  10. Restrorob

    Restrorob LawnSite Fanatic
    Posts: 11,022


    OOPS :hammerhead: Can't even remember the trick YOU told me about.
    Thanks for setting me straight newz.
     

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