16hp Briggs and periodic smoke

Discussion in 'Mechanic and Repair' started by Grassman, Sep 26, 2001.

  1. Grassman

    Grassman LawnSite Member
    Posts: 203

    My 16hp Vangaurd periodically blows a puff of black smoke while mowing. It does this maybe once or twice over the coarse of a day. The engine does'nt lagg when it happens and I haven't noticed any noises either. I did add some Marvel oil to the fuel system, probably a little too much, and tinkered with the adjustment screw on top of the carburator. Do I possibly have it running to rich or could the marvel oil be causing this. Thanks, Russ
     
  2. John DiMartino

    John DiMartino LawnSite Silver Member
    Posts: 2,555

    Your float level might b a little high,casuing it to momentarily fload the engine,giving you the black smoke.If the oil level is a tad high,you will get smoke too,on bumps ,but its usually blue,and happens when the crankcase breather throws some oil into the air filter housing,then the engine sucks it in.
     
  3. Robert Doubrava

    Robert Doubrava LawnSite Senior Member
    Posts: 342

    that black smoke means your getting too much gas to the carb. in other words, its running rich.
     
  4. Toroguy

    Toroguy LawnSite Bronze Member
    Posts: 1,075

    I get the black smoke when starting for the first time each day and the choke is on, as soon as I push in choke smoke stops.

    Looks like a fuel smoke as noted above.
     
  5. vipermanz

    vipermanz LawnSite Bronze Member
    Posts: 1,773

    for some reason mmo doesnt' burn violently , or atleast it doesn't with me
     
  6. Grassman

    Grassman LawnSite Member
    Posts: 203

    Thanks guys. I adjusted the carb again this morning and it didn't smoke all day. Now however, it pings periodically when at full throttle. Is this preignition or could my valves need adjustment? The motor has almost 1900hrs and it's never had anything but basic maintenance. Also, how do you know when the valves need adjusting? Thaks for your help, Russ
     
  7. John DiMartino

    John DiMartino LawnSite Silver Member
    Posts: 2,555

    its borderline lean now,whatever you adjusted,go back a hair towards your original setting,until it stops pinging,but no smoke.When you lean it out,it burns hotter,hotter combustion chamber makes it easier for fuel to preignite.Pining is no good at all,adjust it out ASAP,a lot of pinging will do major engine damage rather quickly.It puts tremdous stress on the rod/piston,and piston top/head.
     
  8. Grassman

    Grassman LawnSite Member
    Posts: 203

    Thanks John. I think I've got it back to normal now, no smoke or pinging. Thanks again, Russ
     

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