I have a 91 f2 and just like a lot of people on this forum I am having a charging problem. I have read just about all the posts on the forum about this and I still have a couple questions and hoped you guys could offer some insight before I shell out the 60-100 for a rectifier.

I checked the output of each of the 3 stator wires and each one is putting out right around 6.3 volts. So, based on that I'm guessing the stator is putting out close to 19 volts when all combined. When I checked the output at the battery at idle I'm getting 12.5 volts and when I bring it up to 5k rpms it doesn't go up much and sometimes it goes down a little. I also checked the stator wires output at 5k and they seem to go down also to about the 5.5 volt area.

After riding for a little while the battery drains down and once the battery drops down to the lower 12v range it won't spin the starter. I surmise that the 12.5 volts coming out of the rectifier/regulator isn’t enough to charge the battery. From what I've read on the forum I'm thinking I might get the rectifier and see what happens but I'd like some opinions please.

Oh, and the guy I got the bike from told me he just put a new stator in it like a few hundred miles ago.

Any help you guys can give would be greatly appreciated.

Thanks!

 

The Voltage comming from all 3 yellow stator wires is too low you should have between 40 ~ 50 volts comming out of all 3 yellow wires, and you should have the volt meter set to AC not DC
how are you checking the stator?


don't always believe what your told, and why did he tell you that???????
has he got the recipt for the stator, sounds fishy

 

Thanks for the help.

The only reason I believe him is because he is a good friend of mine. He changed the stator becuase he thought it would fix the charging problem.

 

I checked using the AC setting and connected the + to the wire coming out of the stator and - I connected to the frame. I got a reading of 15 on 2 of the wires and 25 on the third. I have no idea if this is correct.

 

nooooooooooo!! connect the red probe of the Volt meter to any yellow then the Black probe to another yellow make sure the volt meter is set to AC, and the volt range is above 50v,
then alternate between all the yellow wires untill you have probed them all with the red probe dosent matter which yellow the black goes in as long as you check all 3 yellows with the red you should get between 40 ~ 50 volts if the stator has been changed
then you know for certain it's OK

 

I checked at idle and no matter which 2 wires I tested it was fluctuating between 15 and 16 volts and when I got it up to about 5k it was fluctuating between 50 and 60 volts and again it didn't matter which 2 wires I tested. Does that mean the stater is putting out what it should?

Thanks so much for your help.

 

at 4000 ~ 5000 rpm you should be getting 50V AC, so your stator is ok, now have you checked your battery? I don't mean how much charge is in it, check the acid level, if it's dry throw it away and get a new battery, if you can get hold of a battery tester (high rate discharger) put it across the Batt' terminals with the tops off and if any start to Fizzzzzzzz , your batterys F**ked,
there are more checks to do, but start here and i will help you as much as i can [sm=goodidea.gif]

 

Thanks so much!!!!

I know the battery is new but I'll take it to Autozone and have them test it just to make sure it's ok.

 

mikequinn seem to have this in hand.............. but from the battery check point of view, sounds similar to an old charging problem i had. that was the regulator/rectifier. oddly the first 2 pattern replacements blew the main fuse. the third cured the problem.