Reading the DC output voltage from the rectifier to the battery at various RPM's is a good way to see how battery charging is going.

The values you should get are outlined in the later years of theĀ Honda Shop Manuals which if you don't have one can be downloaded fro free from our companion web site.
Go ahead and get all of them as some things are missing from the early shop manuals.

Paved roads, just more needless government spending...

I pick up my mail in Santa Barbara, California, USA.