imtryin Posted January 7, 2010 Share Posted January 7, 2010 So i have been actively scanning this site for info that would help with this head scratcher that i have going through for a few months now. so far i haven't found anyone Else's thread that has shed any light. The bike: Recently the bike has slowly been holding less and less of a charge, until one day the bike dies on me. I pushed it back to the house and threw the battery on the voltmeter, and it was totally dead, considering the battery was 5 years old i decided to replace it. Brand new battery and no luck 20 minutes of riding and the bikes dead again. So i took it home charged it up and started the bike, i tested the alternator out put. 11.9 volts at idle and i can get it up to 12.4 at 5 grand. So i went through and started bench testing all the components; regulator, rectifier, and stator. all three were a bit out of spec, not terrible though. i decided to start by replacing the regulator and rectifier with an aftermarket combination regulator/rectifier.no luck, The bike was putting out jut the same voltage 11.9-12.4 . i replaced the stator (used stator), same thing. now all components bench test right where they are supposed to, and still not charging. I also did resistance testing on almost all of the wires in the harness between all of the charging components. everything came out good. Any ideas? new rotor maybe? how likely would it be that i needed a new rotor? The bikes only got 8000 miles on it. since this bike has no brushes it needs the battery to excite the stator coil, correct? and if so could a faulty new battery be the cause of this? I've been doing my homework, and I'm stuck. THANKS!!!! Link to comment Share on other sites More sharing options...
Moderator drewpy Posted January 7, 2010 Moderator Share Posted January 7, 2010 So i have been actively scanning this site for info that would help with this head scratcher that i have going through for a few months now. so far i haven't found anyone Else's thread that has shed any light. The bike: Recently the bike has slowly been holding less and less of a charge, until one day the bike dies on me. I pushed it back to the house and threw the battery on the voltmeter, and it was totally dead, considering the battery was 5 years old i decided to replace it. Brand new battery and no luck 20 minutes of riding and the bikes dead again. So i took it home charged it up and started the bike, i tested the alternator out put. 11.9 volts at idle and i can get it up to 12.4 at 5 grand. So i went through and started bench testing all the components; regulator, rectifier, and stator. all three were a bit out of spec, not terrible though. i decided to start by replacing the regulator and rectifier with an aftermarket combination regulator/rectifier.no luck, The bike was putting out jut the same voltage 11.9-12.4 . i replaced the stator (used stator), same thing. now all components bench test right where they are supposed to, and still not charging. I also did resistance testing on almost all of the wires in the harness between all of the charging components. everything came out good. Any ideas? new rotor maybe? how likely would it be that i needed a new rotor? The bikes only got 8000 miles on it. since this bike has no brushes it needs the battery to excite the stator coil, correct? and if so could a faulty new battery be the cause of this? I've been doing my homework, and I'm stuck. THANKS!!!! I would look at your earthing first, take them off ( battery and the one under the seat) and give a scour with green pad and use petroluem gel/copper slip. Link to comment Share on other sites More sharing options...
imtryin Posted February 1, 2010 Author Share Posted February 1, 2010 well, my earthing is good. ive checked and checked and re checked. i ordered a new field coil, and installed it today, and that being the last thing besides the rotor to replace i was hoping for the best. after i put the field coil in, the bike started popping the main fuse, over and over went through 6 fuses. what i found out though was when i unplugged the field coil and turned the bike to on position it wouldn't pop the fuse. so i took the stator and field coil out, and put them back in. not popping fuses anymore, but still not charging. and now the voltage isn't moving at all when i rev the bike. also, i know i did a bad thing but i ran the bike with out the stator wires plugged in. for about 10 seconds maybe. whats the ramifications? any other idea? could the rotor go bad? how? is there any way to check it? thanks Link to comment Share on other sites More sharing options...
Moderator drewpy Posted February 1, 2010 Moderator Share Posted February 1, 2010 well, my earthing is good. ive checked and checked and re checked. i ordered a new field coil, and installed it today, and that being the last thing besides the rotor to replace i was hoping for the best. after i put the field coil in, the bike started popping the main fuse, over and over went through 6 fuses. what i found out though was when i unplugged the field coil and turned the bike to on position it wouldn't pop the fuse. so i took the stator and field coil out, and put them back in. not popping fuses anymore, but still not charging. and now the voltage isn't moving at all when i rev the bike. also, i know i did a bad thing but i ran the bike with out the stator wires plugged in. for about 10 seconds maybe. whats the ramifications? any other idea? could the rotor go bad? how? is there any way to check it? thanks try and steal/beg/borrow another battery of good provenance and see if that helps. i had my bike get slower and slower comming from a rainy long ride and switching off my head lamp helped. turns out it wasn't charging ( 1 month old battery) a new quality battery (yuasa) cured it! drewps Link to comment Share on other sites More sharing options...
XSwheels Posted February 2, 2010 Share Posted February 2, 2010 . also, i know i did a bad thing but i ran the bike with out the stator wires plugged in. for about 10 seconds maybe. whats the ramifications? 10 seconds shouldn't damage things. I ran my stator unhooked for almost a minute with no resulting damage. Link to comment Share on other sites More sharing options...
Speedshop Posted February 2, 2010 Share Posted February 2, 2010 Running with it off loaded won't do any harm, its if you short it out the fun begins. Link to comment Share on other sites More sharing options...
DITCHDIGGER Posted May 20, 2010 Share Posted May 20, 2010 I have a 1980 400 with the same problem,2000 miles on bike need help Link to comment Share on other sites More sharing options...
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