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Problem with B&S motor.

Discussion in 'Mechanic and Repair' started by len pitcher, Jun 29, 2020.

  1. len pitcher

    len pitcher LawnSite Member
    Messages: 3

    I have an 8 hp.B&S motor. Its an intek I/C with OHV. The motor is getting too much fuel
    I have cleaned and rebuilt the original Nikki carburetor. That didnt help. Then ordered an aftermarket replacement carburetor and put it on and it didnt make any difference. I have replaced the spark plug, air filter. It runs a little better at low or mid throttle. It back fires a little also. What am i forgetting?
  2. JoeRagMan

    JoeRagMan LawnSite Senior Member
    Messages: 298

    Check both the needle and seat and the float level. Sounds like that it where the problem is. Good luck.
  3. Nelson M Martin

    Nelson M Martin LawnSite Member
    from Ontario
    Messages: 244

    also check valve lash
  4. Boss302

    Boss302 LawnSite Member
    Male, from SE LA
    Messages: 21

    what is the engine doing that you think it is getting too much fuel?
  5. OP
    len pitcher

    len pitcher LawnSite Member
    Messages: 3

    The crankcase oil is contaminated with fuel. When it is "running" and I shut off the fuel, it tends to run better as the fuel empties out of the carburetor. Choking the motor while it is running causes it to run worse. I suspect the "light" backfiring may be a symptom too?
  6. BigFish

    BigFish LawnSite Fanatic
    Messages: 5,910

    Is the in tank screen intact ? Mayhaps install an in-line fuel filter. Hoses could be deteriorating shedding bits of rubber.
    Unusal fer a new carb's needle/seat to be leaking. Something's causing the needle not to seat properly and stop the gas flow into carb, right ??
    hort101 likes this.
  7. OP
    len pitcher

    len pitcher LawnSite Member
    Messages: 3

    I put an inline filter after it started acting funny. It hasnt made any difference. Something not stopping the gas flow would be my first suspicion too. I have rebuilt the stock nikki carb and nothing changed. I just installed an new, off-brand carb and that didnt change anything either. There aren't many thinhs you can change or even adjust on this carburetor.
  8. BigFish

    BigFish LawnSite Fanatic
    Messages: 5,910

    Pull the bowl off the new bootleg carb and check fer debris, etc.

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