Sorry... B & S again

Discussion in 'Mechanic and Repair' started by Darb, Oct 21, 2002.

  1. Darb

    Darb LawnSite Member
    Messages: 182

    Sorry about the other posts. My computer was acting up and so it ended up posting two threads with nothing on them.

    Ok... let me try this again. I received a 5.3 hp Craftsman Briggs & Straton lawn mower from someone that broke it and instead of trying to fix it, he went out and bought another one. He gave me his old one.

    What he said happened was he wanted to put a mulching blade on his B&S. Well he turned the mower upside down and he ended up leaving the lawn mower upside down for two or three days. When he turned it back over, it didn't work.

    When I got it I checked the oil and there was basically no oil except for a little black paste at the bottom of the dip stick. I put in new oil and then drained it... then I refilled it. I then pulled out the spark plug, removed the muffler, removed part of the carb and removed a small panel that exposed the pistons. I cleaned all these areas out with carb cleaner. The pistons move when I move the crank at the top of the engine. I replaced the plug with a new one and put it all back together again. But the problem is that it won't start and there is a violent retraction of the rewind starter rope when I pull it. Man, that hurts.

    Any clues? I really could use some help... I am not a mechanic, so keep that in mind. Thanks,
  2. mower17

    mower17 LawnSite Member
    from la
    Messages: 26

    Hello. I am new to this forum but I saw your question and I had to answer it. Keep in mind I am only 17 and in the beggining stage of mechanic training but I did run across a similar problem at trade school. When trying to start the mower the cord would get ripped right out of my hand, and it did hurt. Come to find out, the problem was the key on the end of the crankshart where the flywheel bolts on. It was sheared to the point where the spark plug was firing on the wrong piston stroke. All you have to do is remove the flywheel and change the key. The key only costs $1.00. Hope this helps.
  3. captdevo

    captdevo LawnSite Senior Member
    Messages: 932

    ditto.....flywheel key...
  4. Darb

    Darb LawnSite Member
    Messages: 182

    Man, I must really be worse of a mechanic than I thought. I can't find where the flywheel key goes. I removed the flywheel and I see on top of the engine (is that the crankshaft?) I see a magnetic device which look like it might be part of the coil. I don;t see any place for a flywheel key.
  5. captdevo

    captdevo LawnSite Senior Member
    Messages: 932

    should be a slot in flywheel anda half-moon cut in crank to hold key.

    it may be sheared and require a small punch to remove......make sure you find the other piece!!
  6. khouse

    khouse LawnSite Bronze Member
    Messages: 1,465

    Were you trying to start it with the blade off? You need the blade on before starting it up. The flywheel key on your briggs is rectangle about 3/16 x 3/16 x 1/2 inch. That side cover gives you access to the valve springs.
  7. Use flywheel puller or gear puller to remove flywheel
  8. heres the pic

    Attached Files:

  9. Arnold

    Arnold LawnSite Member
    from Wyoming
    Messages: 194

    You can remove the flywheel with out a puller just apply pressure to the under side and tap the top of the crank but protect the threads
  10. Robert Doubrava

    Robert Doubrava LawnSite Senior Member
    Messages: 342

    I've also found that Briggs flywheel keys work better that "generic" brand ones. Just a thought. Good luck!:)

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