stator and/or rectifier

[Anonymous]

i recently bought a 1980 gs850g. the previous owner said it will start up and run fine for as long as i want it to, but if i turn it off after it has gotten hot, it wont restart until it has time to cool down. i havent had it out long enough to confirm this, but i can say that it did fire right up when i bought it, and it made the 5 min ride to my house just fine. after being shut off for about 2 min, it restarted without any problems. it sat for a month or so, and when i went out to try and start it, the battery was totally dead. i jumped it and it fired right up, but after it ran for about 30 min and was turned off, the battery was still totally dead (wouldnt even power the lights). jumping it starts it right up every time, for what thats worth. so thats where i am now. this is my first bike, so i dont know much about pinpointing probelms, but the previous owner had told me the rectifier needed to be replaced. he didnt say anything about the battery, but it would seem to me that needs to be replaced as well. does this indeed sound like a rectifier problem? i plan on going through the series of steps listed in the stator pages (as soon as i clear away the 6 foot snow drift in front of my garage :x ) to identify for myself the source of the problem, but i have a real quick question... maybe i missed it, but if i understand correctly, if i have a bad rectifier, i dont necessarily also have bad stator. is that correct? then on the other hand, if i have a bad stator, is it possible that my rectifier is still good? or does a bad stator always kill the rectifier? many thanks for any help you can give the new guy on the block... -andrew quinn

[Wingnut]

A bad regulator does not necessarily mean the stator is bad and visa versa. However, if you run the bike for any length of time with a bad regulator it can and probably will damage the stator. Sounds like that may have happened on yours. The first thing to do is get a good battery. Start the bike and let it run a minute or two and check the voltage at the battery with the engine at speed, like 4000 RPMS. If you are reading around 14 volts the charging system is good. Much below 13.5 and something is wrong. These are not the exact numbers or RPM?s but it will give you a quick check to see if you need to go further. If you need to go further go to the stator papers and start there.

[SqDancerLynn1]

Before you do any checking clean the stator & reg connections

[argonsagas]

Before you do anything else, go to the "In the Garage" section on this forum and print out something called "The Stator Papers". This will give you all you need to do a full check of your charging system.

You need to charge the battery slowly, and fully, before doing any electrical checks.

For the stator, you can pull the connections for all the wires from the stator and do your voltage check there. The wires are disconnected before starting, but the check itself is done with the engine running.

No, this will not harm the battery.