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Please Help 25hp Kawasaki

Discussion in 'Mechanic and Repair' started by abiggcountry, May 3, 2012.

  1. abiggcountry

    abiggcountry LawnSite Member
    Messages: 5

    Man I'm lost. Have a Husky ZTR with 25 hp kaw. motor. I have a problem where motor works fine for about 20 or 30 mins. then starts running on one cylinder. I am a mechanic by trade and been working on this stuff for years but this one has got me. I have it narrowed down to an ignition problem. I have adjusted valves cleaned carb. and new plugs. So here is what it is doing. Coil on right cylinder was not firing pulled wire on left cyl. and engine quit. So i reversed the coils and now if i pull right plug engine quits. That's what I expected but what I didn't expect is that now the original bad coil started working on the left cylinder and now the good coil is not firing on left side. This one has got me scratching my head. And to confuse matters even worse if you start mower on one cyl. with left plug wire unhooked it will start on right cyl. but if you plug both wires up and pull left plug wire it will die. I have pulled ground circuit to coils with same results. Any help would be appreciated . thanks.
  2. sjessen

    sjessen LawnSite Platinum Member
    Male, from Knoxville, Tn
    Messages: 4,510

    Sure sounds like the problem is in the coils. Usually best to replace both at the same time. My experience is they last about 750 hours or so.
  3. teckjohn

    teckjohn LawnSite Senior Member
    Messages: 282

    normally its the carb
  4. piston slapper

    piston slapper LawnSite Platinum Member
    Messages: 4,335

    Need some engine numbers....some coils are cylinder specific
    Posted via Mobile Device
  5. dwost

    dwost LawnSite Bronze Member
    Messages: 1,667

    Hi all, I had a similar issue this week. I was out mowing and after 15 minutes the motor started sputtering and died. I checked everything over and let it cool down. I went to fire it up again and it started briefly then did the same thing. I pulled both plugs and they had a lot of fuel on them. I cleaned them up and checked for spark. One cylinder was fine the other is not throwing a spark. I'm going to try and pick up a new coil tomorrow. One question. This is on a 26 Kawi LC, model FD731V. In looking up the coil numbers I'm given two different ones but they look to be interchangeable? Anyone know the specifics on this model? The two numbers provided are 21121-2105 and 21121-2106. TIA!
  6. whosedog

    whosedog LawnSite Senior Member
    Messages: 730

    I agree,my coils went at 550 hours.I tried everything else,new plugs ,filters,new fuel pump;now after replacing the coils it runs fine.
  7. dwost

    dwost LawnSite Bronze Member
    Messages: 1,667

    I went ahead and ordered both. Fingers crossed!
  8. dwost

    dwost LawnSite Bronze Member
    Messages: 1,667

    It's fixed. I replaced both coils and it would start then die immediately. I pulled the air filter and cleaned out the carb. Still nothing. After cranking it with the carb open I noticed an over abundance of fuel leaking out. Very weird so I pulled off the fuel line at the pump, cleaned the filter and then blew out the pump. It then fired right up. It seems the motor was getting immediately flooded fouling the plugs. I'm still at a loss why the pump was overworking but I cut with it tonight without issue. So I probably didn't need new coils but they are in and I'll keep the old ones for spares.

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