Briggs and Stratton carb help?

Discussion in 'Mechanic and Repair' started by dbsound, Apr 23, 2008.

  1. dbsound

    dbsound LawnSite Member
    Posts: 15

    So, I've got a Briggs and Stratton 3.5 classic(yes, I know they're not great, but it's for a rental property, so you can't let renters tear up a good mower). Anyway, it won't run. It's only about 6 months old, and probably only has about 10 hours on it. I've changed the carbuerator gasket(which go bad on the Classic, ALOT), and there was no change. Dumped all the gas, and put fresh in. Nothing. It WILL prime and start, but won't feed itself after the prime start. If I keep hitting the primer button, it will stay running, as long as you pump it. Everything still looks new on the whole engine.

    Why won't it feed itself?
    THANKS SO MUCH for your input.
  2. jkason

    jkason LawnSite Senior Member
    Posts: 548

    Did you change the carb gasket or the diaphragm AND gasket?

    If you changed both, I would suspect a warped mounting surface. Only remedy is replacement. (Under warranty, of course.)
  3. dbsound

    dbsound LawnSite Member
    Posts: 15

    That's the double gasket kit, right(thin one, and a thicker one). If so, yeah, I replaced both. It's like it's just not drawing gas into the carb.:cry::cry::cry:
  4. Restrorob

    Restrorob LawnSite Fanatic
    Posts: 11,023

    Did you remove the screen from the bottom of the carb and spray carb & choke cleaner through the port in the center ? What about the screen in the bottom of the long white fuel pick up tube, Did that get cleaned ?
  5. dbsound

    dbsound LawnSite Member
    Posts: 15

    I blew through it. I'll try a better cleaning of it, tomorrow.
    THANKS so much.
  6. LawnVet

    LawnVet LawnSite Member
    from SE MI
    Posts: 220

    Does the carb have electrical wires coming out of the bottom? If so it could be the, unnecessary, anti-backfire device. You can bi-pass that if it is the problem.
  7. dbsound

    dbsound LawnSite Member
    Posts: 15

    No. No wires.
  8. dbsound

    dbsound LawnSite Member
    Posts: 15

    So can someone explain to me - after it's primed, how does it draw the gas?
    Up the long tube?
    What's the other smaller tube, with the cylindrical screen on it?
    What makes it draw the gas?

    This damned thing has SO FEW hours on it, I can't figure out why it won't stay running.
  9. rclopez1118

    rclopez1118 LawnSite Member
    Posts: 15

    Your problem is the carb, and needs to be cleaned very well. make sure every small hole is clean, and the diaph kit is installed in the right order. oh yeah,..make sure the primer bulb is working right too.
  10. Restrorob

    Restrorob LawnSite Fanatic
    Posts: 11,023

    Post the model and type numbers off the top cover above the spark plug so I can see exactly which carb you have.

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