25HP Kawi

Discussion in 'Hustler Turf Equip (Archived)' started by TiredOfWalking, Nov 1, 2004.

  1. TiredOfWalking

    TiredOfWalking LawnSite Member
    Posts: 40

    Hi,

    I have a 2001 Super Z with a 25hp Kawi on it. The engine only has about 55 hours on it. When I shut it down it backfires almost every time. I tried letting it idle for about 30-40 seconds before shutdown and it still backfires. I tried shutting down at 1/2 throttle, 3/4 throttle and full throttle....still back fires.

    Is this a problem I should get addresses? Can it result in harm to the engine? Any suggestions would be much appreciated.

    Thanks in advance.
     
  2. mowerconsultant

    mowerconsultant LawnSite Fanatic
    Male, from Syracuse, NY
    Posts: 9,761

    We just released a service bulletin to our dealers about this.
    Here is what it says....

    Subject: Exhaust backfire
    On Hustler Z, Mini Z and FasTrak mowers, operators may experience exhaust backfire
    during engine shutdown. The backfire can vary depending on exhaust temperatures and
    engine RPM. Backfire will not harm the engine or the muffler. This is a common
    condition and can be minimized by following the recommended engine manufacturer
    shutdown procedure.
    Engine manufacturer shutdown procedure:
    Rev engine to 3/4 to full throttle and turn off ignition key
    This procedure lowers the vacuum in the carburetor which results in minimal fuel reaching
    the muffler and minimizing or possibly eliminating backfire.
     
  3. TiredOfWalking

    TiredOfWalking LawnSite Member
    Posts: 40

    Thanks, PJ.

    It's good to know it won't hurt anything. Will continue to shut down at 3/4 throttle and see what happens.
     
  4. lampeslawnservice

    lampeslawnservice LawnSite Senior Member
    Posts: 323

    Let it run at idle for about two or three minutes it will solve your problem. I always cringe when I'm in ahurry but sometimes you just have to do it. If I let it run for about 3 minutes while trimming it doesn't backfire
     
  5. Doc Pete

    Doc Pete LawnSite Gold Member
    Posts: 3,469

    FWIW,
    I have three 23/25hp Kaw's and don't seem to have a problem with the backfiring. The fuel shutoff on the carb is supposed to take care of the problem. Is it possible you are running with slightly dirty filters allowing the motors to be richer than they should????? Also, check to make sure the carb float level isn't just a tad too high, or that the valve seat on the carb doesn't leak just a wee bit.
    Pete
     
  6. JHE

    JHE LawnSite Member
    Posts: 102

    I have a 2004 Hustler Z with a 25hp Kawasaki. It backfired out of the crate and has less than 50 hours on it and still does it. I have not tried the rev to 3/4 throttle thing - just learned about it in this thread. But if I let it idle for a while prior to shutting down the backfire is definitely smaller/less.
     
  7. TiredOfWalking

    TiredOfWalking LawnSite Member
    Posts: 40

    Well, I've tried both the 3/4 throttle things and idling for a few minutes prior to shutdown. The idle thing works better for me.

    Thanks for the tips
     

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