Ken........unlike modern 12V alternators, the original 6V generators do NOT charge at idle. You need about 1/4 throttle. As fer reading 3-amps, semi-normal. Me? Before I did ennythang, I'd re-polarize yer 6V-genny. Just "arc-spark" the side-by-side ARM and BAT screws on yer squarecan voltage regulator; engine OFF. I use a wide blade stubby screwdriver, you can use bailin'warr iff'n you want. You can "polarize" as many times as it takes to feel warm'n'fuzzy ...er... charged.
Batterys don't live forever, and iff'n yer battery is semi-dead, it takes overnite to re-charge it at about 3-amps. Ennythang faster will BOIL yer battery acid out. Which BTW, you need to check and "top-up" with distilled water. Iff'n you run outta battery acid/water you will WARP yer LEAD plated and then will DEFINITELY need a NEW battery. .......the charged Dell