! Help needed with my vfr 1994 Charging System !

I just got a 1994 VFR 750,,
Im new to this bike so please excuse my lack of knowledge,,,
BUT if anyone can help me i would be very thankfull )

Problem: Bike dies after about 2 hours..

Observations:
Battery charges fine to 12.5v
afrer running bike for about 2 hrs bike will die if alowed to fall below 5k rpm.
Also Battery is to dead to start ,, must be jumped...
If voltage at battery is measured while bike is in this state is is 10.6 -- 10.0 volts..

Info gathering and troubleshooting thus far:
Replaced battery,,,,,,, same thing,,
unpluged connector from stator with 3 yellow wires and ohmed between 3 wires... .5k omes between all three respectivly in any combo,,, also dead open between any plug and ground..

with all pluged in and bike running at 5k and a battery that was charged to 12.5v fresh in the bike voltage will never get over 13v,, most of the time its lower..

rectifier "seems " to ohm out ok... I think,, but when i measure at the plug for the rectifer i see voltage from the stator on all 3 yellow wires,, but only 12.5 on the pin 1 -- output to charge battery,,,

I BELIEVE this is the rectifer that is bad..??

any thoughts?? HELP...

feel free to call me at 304-826-7031
or amswer post, or e-mail.... [ william.catalina@,mylanlabs.com ]

 

Yep, rectifier should charge about 14.5 volts at 5K rpm. Time for a new one.

 

This happened to me when I bought my '97. I think it's a VFR Rite of Passage.

I found a pretty cheap solution: I installed an R/R from a 2000 Yamaha R1. You have to carefully remove the clear plastic wire harness (while leaving the individual spade connectors intact) and connect the individual connectors to the "male" terminals on the Yamaha R/R. The Yamaha unit cost me about $50 on eBay. You have to get a *little* creative with the mounting, but it's an easy job.

I also installed a volt meter... after the fix, it always reads between 13.8 and 14.3 volts, depending on RPM. Good enough for me!