7 horse briggs backfires and pops at an idle

Discussion in 'Mechanic and Repair' started by Robert Doubrava, Aug 31, 2001.

  1. Robert Doubrava

    Robert Doubrava LawnSite Senior Member
    Posts: 342

    i was just wondering if this problem could be fixed somehow. i have the model, type, and code if it's useful to someone.

    model-170702
    type-151701
    code-80032709


    any help is appreciated.
     
  2. Robert Doubrava

    Robert Doubrava LawnSite Senior Member
    Posts: 342

    i forgot to say, it is a vertical shaft engine. i believe it is an out of production engine, too.
     
  3. khouse

    khouse LawnSite Bronze Member
    Posts: 1,465

    tell us more. does it pull fine otherwise? does it have good compression? does it backfire just above idle? ect.. this will help us help you.
     
  4. Robert Doubrava

    Robert Doubrava LawnSite Senior Member
    Posts: 342

    it has good compression. its pretty hard to start, but it runs good if you have it at top speed. it is about 20 years old, but my dad and i overhauled it in about 1995-96.
     
  5. khouse

    khouse LawnSite Bronze Member
    Posts: 1,465

    My guess is that your intake valve is not seating. Do you have a compression guage? What did you do to the valves and seats on the rebuild?
     
  6. Robert Doubrava

    Robert Doubrava LawnSite Senior Member
    Posts: 342

    we bought new piston rings, a new rod, a gasket kit, i am not sure what else.
     
  7. Robert Doubrava

    Robert Doubrava LawnSite Senior Member
    Posts: 342

    my dad has a compression gauge.when we over hauled it, we replaced the valve seats, and we made sure that they were still good.
     
  8. khouse

    khouse LawnSite Bronze Member
    Posts: 1,465

    I would like to know the compression on your engine. First dry psi. Then give me the wet compression by adding a capfull of oil in the plug hole then retaking the test.
     
  9. Robert Doubrava

    Robert Doubrava LawnSite Senior Member
    Posts: 342

    ok. when my dad is not working we'll try it.
     
  10. khouse

    khouse LawnSite Bronze Member
    Posts: 1,465

    robert, just post back with your readings. good luck
     

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