Does keeping petcock on for long time drain all petrol by flooding engine?
No, keeping petcock on for long time can’t drain all petrol by flooding engine as the engine doesn’t have more fuel containing capacity than fuel-tank, the reason for advising to turn petcock to OFF position because due to gravity some amount of petrol may evaporate or flow to the engine unnecessarily when the bike is parked and not being used, and yes it will affect the fuel efficiency.
Bajaj doesn’t recommend installing kick start in Avenger bikes and it is also a complex task which if not done by some expert may cause permanent damage to the engine and it is expensive too and moreover such type of modification also voids engine’s warranty.
You can install pilot lamp on headlight or white color projector light but they should not consume more than recommended voltage else battery will drain soon, may develop some fault and installing such types of lights can also void battery’s warranty.
Questions about Bajaj Avenger