Voltage problems 48 inch scag walk behind

Discussion in 'Mechanic and Repair' started by scagmaster, Oct 28, 2007.

  1. scagmaster

    scagmaster LawnSite Member
    Posts: 8

    Anybody, Please help I have a 48" scag manual start. I am having problems with the blade engagement. When I start the engine the blades will run at low idle, as soon as I throttle the engine up pass half and full speed the blades will disengage. I am losing DC voltage from the rectifier. I have 45 volts AC out of the stator at full speed, when I throttle the engine down to were the blades will engage it reads 22 to 25 volts AC. The rectifier at this point read 8 to 9 volts DC then when I throttle up the engine I lose the DC voltage. I have replace the stator with a used stator. I have replace the rectifier with a new one. I have check all the switches all seem to be in working condition. Please help me if you can!!!!!!!
     
  2. Restrorob

    Restrorob LawnSite Fanatic
    Posts: 11,024

    Are you loosing this voltage according to your meter or just the fact the clutch shuts off ?

    Also, Where is it are you testing this voltage at ?
     
  3. scagmaster

    scagmaster LawnSite Member
    Posts: 8

    With my meter lead on the hot wire to the clutch and the other lead to the ground terminal the voltage is lost as I throttle up.
     
  4. Restrorob

    Restrorob LawnSite Fanatic
    Posts: 11,024

    Put your ground test lead to a engine/frame ground and check again, You could have a ground fault in the harness.
     
  5. scagmaster

    scagmaster LawnSite Member
    Posts: 8

    but why would it work at the slower speed. It stop working at the same spot on the throttle
     
  6. scagmaster

    scagmaster LawnSite Member
    Posts: 8

    I'll check it tomorrow and get back to you
     
  7. scagmaster

    scagmaster LawnSite Member
    Posts: 8

    restrorob, I have completely eliminated the safety switches, (neutral, handle, and cut off switches. The only thing that was connected was the main wire coming from the stator to the rectifiter then I put the meter lead on the engine ground and the hot wire from the rectifier still the same result. So I have eliminated the entire circuit. So I am back to the rectifier (which is brand new) I know that don't mean nothing. I purchase the stator used but everbody I ask said, that I should be getting 45 volt Ac out of it and I am at full throttle and about 22volts Ac at half throttle. so maybe the stator is not working properly. Any suggestions thanks for all your help
     
  8. Restrorob

    Restrorob LawnSite Fanatic
    Posts: 11,024

    Post me the engine model AND spec numbers, Also the SCAG model and serial numbers.
     
  9. scagmaster

    scagmaster LawnSite Member
    Posts: 8

    The engine- kawasaki model # FC420V-AS27
    The engine- Serial # FC420VD76161
    The engine- family # YKAX8.4232CA
    The engine- Model Year 08/00
    The mower- scag model # SW48A-14KA
    The mower- Serial # 7090140
     
  10. Restrorob

    Restrorob LawnSite Fanatic
    Posts: 11,024

    Well, You can perform the below test on both the regulator and stator and hope you find one of the two bad, If not the only other thing that comes to mind is weak magnets inside the flywheel.

    There is no set max output on the stator, Only minimum output at the specified RPM's.

    [​IMG]



    [​IMG]


    If I had to guess, It looks like the stator is not up to par.
     

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