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Hot!21 hp bs gold alternator question

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woodsyman762
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2020/09/09 17:10:03 (permalink)
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21 hp bs gold alternator question

Hello everyone have a weird one for you I think I know what's wrong but cant find any verification so I will ask you all.
I bought a gt5000 craftsman mower that the guy put a newer motor in originally it had a kolher. Well the motor runs awesome till you engage pto then the amp gauge discharges so I assumed that meant pto was going out so I replaced it . same deal I know this motor only has a duel circuit alternator 2-4 amp I am guessing that's not enough to operate the pto and the tractor as it runs lousy when engaged if you fiddle with throttle you can use it but its a pain in the you know what. There is 19 volts at connector while running I think I need to put bigger alternator in but can find nothing that says that's possible. or should I count my losses already spent more than I cared to on it. The motor is a briggs and stratton model 331877-0869-g5

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    AVB
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    Re: 21 hp bs gold alternator question 2020/09/10 08:22:10 (permalink)
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    Of course it runs lousy. It is way under powered as the Kohler was a 26 gross hp and with the 54" deck you need that extra hp. The Briggs is only 21 gross hp. It pushing it to be on a mower that is 42" which I am using here due that I let my grass to get over grown.
     
    As for the electrical problem yes the stator can be upgraded by install the 10-16 amp stator and a matching voltage regulator. But first you need to determine if your PTO clutch current draws is under 7 amps as if it is above that then it has a partial short. IF the current draw is under 5 amps you can just add a voltage regulator for the dual circuit stator but it is better to change over to the 10-15 version and regulator. It just that the lights circuit will need changed over to a switch circuit by adding a on/off switch or rewiring to the ignition switch.
    woodsyman762
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    Re: 21 hp bs gold alternator question 2020/09/10 14:02:39 (permalink)
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    its a 48 inch deck and it cuts great doesn't even bog down really I cut 4 ft weeds with it no problem just not running right all checks are where they should be original motor was kolher 20 hp with a 15 amp charging circuit when engaged I have 11.8 volts at pto and battery just low enough to cause my problem  question is can I replace the alt with a 16 amp one from what I can gather the flywheels have different size magnets but I have found some contradictory statements on that any idea don't want to get into changing flywheels they cost more than the tractors worth
    woodsyman762
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    Re: 21 hp bs gold alternator question 2020/09/10 18:09:25 (permalink)
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    think I got it figured got the original wiring schematic and pulled harness the  black wire from coil to the switch was jumpered to the pto switch cut that wire and it runs as it should it must have been backfeeding from pto and messing with coil output 
    Roy
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    Re: 21 hp bs gold alternator question 2020/09/10 18:27:57 (permalink)
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    If the coil sees battery voltage it won't last long!
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