Ok, so you have the battery grounded and the stator is putting out voltage. Check the amperage across the battery terminals with the bike running and all of the lights off. Be careful not to blow the fuse in your meter. Most will blow over 10 amps, but I doubt you're putting out that much. If you get anything, you're charging the battery. If you get no amps across the battery, be sure that the positive and negative from the battery and the two leads from the coil are connected to the rectifier in the right positions. If everything is hooked up right, check the four diodes in the regulator.