2000 vfr charging issues

hi, i have a 2000 vfr 800 and it has a strange charging issue, the battery is new and is sitting at 12.7 volts when you start the bike at tick over it is charging 13-13.5 volts but rev it any higher than tick over it stops charging, i have changed the regulator/rectifier and both the original and the new one have the same problem. the stator is putting out the correct ac voltage at 4.5k revs that the repair manual says 50volts from memory. i have checked the earth block, all connectors along the charging line, the 30amp fuse which had melted has been changed. does anybody have any other ideas to check. thanks

 

Couple thoughts... Seems it's unlikely to be the R/R since you had the same result with both. So, I'd investigate the stator and wiring more closely. Fully charged battery should be 13.0-13.2V, but 12.7 should be enough and the battery is new.

1. Did you check the stator resistances and for continuity to ground?
2. Did you disconnect the connectors in the charging system, clean them/apply conductive compound (Oxgard or comparable) to the terminals? Visual check doesn't address the issue of oxidation in the connectors.

 

h, thanks for the post, i did check the stator resistances on the 3 sides and to ground and it was per the manual. i disconnected all the plugs and cleaned them i dont have any of the compound but i will get some and try it, i am going to borrow one of my friends batterys and test it again with the other battery just to confirm that it is not the battery.
i have only had the bike a few months and have only managed about 10 miles so far and it has been nothing but trouble so far, it had an issue with an air pipe causing the engine not to run properly, the battery had a large draw on it when everything was off which turned out to be an alarm problem, now the charging problem. hopefully i will get it sorted soon and get some miles on the bike

 

There's a way to check the voltage drop from the R/R to the battery, might want to look into that, believe it is in the shop manual. It should be close to 0. Only other thought is that it might be possible for the stator to pass those tests but fail under load.

 

I use to check connector frequently to keep an eye on a known weak point.
A few months ago I decided to clean it and treat it with electrical anti corrosion paste and felt better.
On a whim, a month later I decided to check on it to see how it was going, to my surprise, the connector was melted.
I have now got rid of the bloody thing a soldered the connections.
It took a few minutes and I have now got rid of the problem for good.
Don't forget that many people here have replaced the connector with heavy duty ones, and have still had the problem of melting.

 

delactic gease

 

It would seem the voltage at the regulator is rising enough to shut off charging, so there is a bad connection someplace between the R/R and the battery. Check voltage between R/R + (red) and battery + with engine revved above idle. Check R/R - (green) to battery -. Each case, there should be very little voltage drop, under half a volt. Check battery - to frame. If you find a couple of volts across any of those circuits, trace the wiring and connectors. Check that the red fuse wire hasn't burned out. It's designed to burn out before the rest of the wiring harness. Good luck, you'll find it eventually.