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.
I've never seen a single layer petcock diaphragm. Have a look at http://www.thumpertalk.com/topic/922.../#entry9626847
. Are you sure the diaphragm's plunger o-ring or the multi-hole rubber selector gasket did not go bad in combination with a leaky float valve?