I got this off internet, might be of use.
No, the BMW R1100 and R850 models will not only start if neutral is engaged. Factory specifications allow the motorcycle to start while in gear, provided that the clutch lever is fully pulled in and the side stand is raised.
The motorcycle utilizes a parallel safety circuit to ground the starter relay through two distinct paths:
1. The Neutral Switch Path: Works when the transmission is in neutral (indicated by the green "N" light).
2. The Clutch Interlock Path: Works when the transmission is in gear, as long as the clutch lever is pulled in to close the microswitch at the handlebar.
Why Your Bike Might "Only Start in Neutral"
If your R1100 or R850 strictly refuses to crank while in gear—forcing you to shift into neutral every time—it is almost always caused by a faulty clutch safety switch.
Because the transmission neutral switch on these models is notorious for getting "lazy" or failing over time (due to its position behind the swingarm where it easily collects grime and gear oil), a broken clutch switch leaves you vulnerable. If both switches fail, the bike will not crank at all.
