Briggs 10.5 hp engine won't start...

Discussion in 'Mechanic and Repair' started by TROTTMAN, Jul 13, 2003.


    TROTTMAN LawnSite Senior Member
    Messages: 397

    Yesterday I was mowing and my friend was using my walk behind. He turned it off because some guy needed to borrow gas and then he couldn't get it to turn back on. We spent a long time trying to get it to fire, and it finally did about 20 minutes later. It started really slowly and finally putted up to rpm.

    Later that day I used it again and I could just BARELY get it to start. It took me about 5 full minutes to get it running. It would try to fire and turn over for a few seconds and die. I was finally about to get it started and I used it for that lawn. It sounded like it was running decent but would blow puffs of smoke every now and then. It also didn't cut well at all (lower rpms perhaps).

    I tried starting it later with no luck, I just can't get it to fire. It will turn over for 4 seconds at best and die. It has a brand new air filter and oiled prefilter, and plenty of oil (just changed last week).

    Any ideas of what I can check etc? How much will a new engine run me if I need to get it. Oh yeah, its a B&S I/C 10.5hp. Can it be rebuilt? Thanks.
  2. Northern has a 10.5 briggs engine for $360.

    Yes they can be rebuilt.
    To trouble shoot I would
    make sure choke is working properly
    Drain fuel tank & replace with fresh
    Clean carb
    replace plug
    check armature gap

    TROTTMAN LawnSite Senior Member
    Messages: 397

    Okay thanks. It has a fairly new plug.

    Today I ran it, it had trouble starting, but ran all day. I started it and didn't shut it off even driving because I was so worried. However I did shut it down to get it to my last lawn and it started up fine for some reason.
  4. Rustic Goat

    Rustic Goat LawnSite Bronze Member
    Messages: 1,194

    You ought to check items Bob suggested anyway.
    Even though it's a fairly new plug, pull it, check its condition and gap.
    Sounds like fuel and/or choke problem.

    TROTTMAN LawnSite Senior Member
    Messages: 397

    Yeah, I tried taking it to the shop today since it had a hard start again (did run all day). They don't have time to mess with it. It started fine while I was there and at the lawns I did later. Wierd huh?
  6. Robert Doubrava

    Robert Doubrava LawnSite Senior Member
    Messages: 342

    Make sure that when you remove/re-install the spark plug that you do it when the engine is cold. If you put the plug back in while the engine is hot you can pull out the threading inside the head of the engine if you tighten it too much. I did this recently(on accident) and I had to wait 2 days for them to get to it and I had to spend about $22.00 to get a helocoil installed. So be careful.


    TROTTMAN LawnSite Senior Member
    Messages: 397

    Alright thanks! I did this with an older mower that didn't work, the plug mysteriously would never get tight, and the engine never quite did start hehe.

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