Originally Posted by MJS
Had the vacuum diaphragm go bad in my DRZ and fill the engine with fuel. It is only a single diaphragm and any leakage goes directly into the intake manifold through the vacuum port downstream of the carb. Gravity will take it straight into the cylinder.
Yes this... And it is not so rare once the bike gets old with ethanol fuel. We also had this happen in an old Suzuki Bandit which belonged to a friend with the same system.Manual petcock is the only really safe system IMO.Basically that big gas tank tries to unload its fuel to the lowest point it can....your crankcase and garage floor