It looks like this thread is long in time (years) so I am replying a year-and-a-half later to rsamsel regarding his intermittent electrical problem with his grips, lights, (and I assume his tachometer) while the engine still runs fine. I'm not sure he will ever see this post but it is available to others who come across this thread in the future.
The problem is most likely the engine harness electrical connector is working it's way loose. These plastic connectors have a locking tab that often wears down after being unplugged and then plugged back in several times. The engine vibrations gradually work the connection loose enough that the engine runs fine but the tachometer doesn't register and all lighting and grip heating goes dead. The connection is down low and at the rear of the MAG (right) side of the engine. It is in close proximity to the steering post which may also be a contributor to working the connection loose. The fix is simple...push the connection tight and snug up a zip tie after threading it between the wires on each side of the connection. Go enjoy your now reliable sled!