my charging system is not up to par. First I put a new battery in it. charged new batt overnight and it was holding 12.9V. After a couple weeks the voltage across the batt terminals dropped to 11.5V. during this time i ran the bike for at least 20 mins almost everyday.
I charged the battery again and put my multimeter on the terminals and ran a little test:
engine off - 12.3V
idle (1400rpm) - 12.5V
2000 rpm - 12.6V
3100 rpm - 12.8V
4000 rpm - 13V
the surface of the rotor is rusty, im gonna shine it up with some 400 grit. also there is a groove in it, not sure if this is ok or not, does anyone know whats up with this?
there is also a small amount of oil leaking from the engine case somewhere into the altenator. this is a little scary, im not ready to disassemble the engine case, for the time being i can just keep it clean.
the rectifier has continuity in one direction and matching resistance across all three yellows. so its OK
the field coil has two leads and measured 4.3 ohms. manual says 4.9 +/- 10% so im assuming its OK
the stator coil has has three yellows - measured 0.9, 1.0, 1.1 ohms across each one. manual says 0.35 +/- 10% so is it within spec??
UPDATE I have since changed the stator coil with a used one from ebay and now the charging system works as should. At 4500 rpm it makes 14.5V