12.5 kawi backfiring!

Discussion in 'Mechanic and Repair' started by cariboulou, May 26, 2006.

  1. cariboulou

    cariboulou LawnSite Member
    Posts: 160

    Any advice on keeping my exmark 32" with mulching kit from backfiring? I run it only in backyards with gates and run it at 80 to 100% throttle. when I park it on the trailer, lower the throttle, and shut it off it backfires out the muffler. Is there some screw that is making it run rich?
     
  2. Restrorob

    Restrorob LawnSite Fanatic
    Posts: 11,023

    Let it sit on the trailer and idle for a couple minutes (cool down) while loading other equipment then shut it down and see if that doesn't help.
     
  3. cariboulou

    cariboulou LawnSite Member
    Posts: 160

    never had to do that with my 36" scag with same engine. friend of mine said it might my running rich, since when it get done with backyard, I throttle down to 50%, gear down to 2nd and drive it up ramp and put it in sideways, a couple of minutes total and then shut it off.
     
  4. Restrorob

    Restrorob LawnSite Fanatic
    Posts: 11,023

    Pull the spark plug and look at it, If it's black it's running rich and needs the carb. cleaned and a new float needle valve. What is the model number on this engine ? Do both these units have the same hours on them ? And how many would you figure ?
     
  5. lawnmaniac883

    lawnmaniac883 LawnSite Silver Member
    Posts: 2,613

    Try shutting down the engine at just under 1/2 throttle.
     
  6. khouse

    khouse LawnSite Bronze Member
    Posts: 1,465

    shut the engine off at 3/4 throttle.
     
  7. cariboulou

    cariboulou LawnSite Member
    Posts: 160

    cleaned off the spark plug and want to change it out. after I cleaned it I gapped it at .25 and it didnt backfire this time. It has an autolite plug in it on a kawi 12.5. Id like ngk, does anyone know the part no. for this engine and correct gap?
     
  8. MowerMedic77

    MowerMedic77 LawnSite Bronze Member
    Posts: 1,164

    Kawi FB460V plug:BMR2A, gap: 0.024-.028
     
  9. lawnmaniac883

    lawnmaniac883 LawnSite Silver Member
    Posts: 2,613

    An old plug isnt going to cause a backfire...
     
  10. Restrorob

    Restrorob LawnSite Fanatic
    Posts: 11,023


    Hmmmmm......Kind of like you can't balance a blade on a nail huh. :waving:
     

Share This Page