Hello? Is this thing on? A loose O2 sensor would not make the tach sweep or cause the bike to shut off.

But any of these things would:

Quote Originally Posted by Cooter View Post
Check for corrosion in your ignition fuse/relay circuit in the fuse box (all the relays are the same so swapping them around is OK), including the red run switch.

Check all grounds near the steering neck, a known problem with Buells.
Are your battery terminals tight? Take them off and check for corrosion there too.