Not to hijack things here, but reading this thread got me wondering. Just purchased a 1990 R100GS of unknown history and it ran great for the first 1000 miles that I've had it. Mileage is around 40,000 miles. Now the bike is shutting down on me with no real constancy. I might ride 5 miles, or 25, or 100 miles, and usually it will start back up in 5 to 10 minutes. I just replaced the old cracked coil - no luck, still does it. Looking at cleaning all the electrical contacts next. Who thinks its the Hall sensor, as I am starting to lean in that direction?