Ok so I've been investigating some electrical quirks my bike has and wanted to see what you guys thought. I've gotten lots of pointers reading other posts but haven't found one quite like this.

When testing the voltage to determine R/R failure, I found that at 1000 rpms with a fully charged battery I get a reading in the low 14 volt range. However when increasing the rpms of the engine, the voltage reading drops to say the mid to high 12 volt range around 4000 rpm, instead of going up. This is the case when the battery is not fully charged as well with the exception that the voltage reading at 1000 rpms is in the mid 13 volt range. I've checked resistance in the stator wires and none are grounded and have a 7 ohm reading across all three wires.

Bike is a 98, with finned R/R, so PO must have replaced it at some point. I believe it is a later Honda R/R unit, but alas I forgot to grab the part number off it before I put it all back together, so it very well could be some Chinese piece of junk causing all my frustrations and bewilderment. Could the R/R really be trying to regulate the voltage a bit too soon? I kinda would expect the opposite in most cases.

 

If it's dropping to under 13 volts, you're running off the battery (not charging). Since the stator checks out, the R/R is the most likely culprit. I can't explain the drop as rpm increases, but electrical gremlins can screw with your mind.

Check the R/R connector for corrosion and a tight fit. Use silicone dielectric grease on the connector. And check the ground. If those are good, the R/R is the best bet. And a lot cheaper/easier than stator replacement.

 

R/R, classic failure. As RPM increases more power is generated by the stator, meaning the R/R has to dissipate more heat, causing the Diodes to fail at the higher temperatures, leading to lower (no) voltage out of the R/R.

Get a Yamaha one and do the swap as described in the forum Knowledgebase.