If the fuel petcock is
leaking or excessively contaminated, it should be removed from the fuel
tank and inspected.
Remove the fuel tank and position it so that fuel will not spill when
the petcock is removed.
Remove the petcock and inspect the filter screen. Replace the filter if
Remove the screws on the front and rear of the petcock and remove
the plate, gasket, lever, and diaphragm.
Inspect all components and
replace any that are damaged. If the diaphragm is in any way damaged,
or the petcock body gasket surfaces scratched or corroded, the petcock
assembly must be replaced. If there is abrasive damage to any
component, the fuel tank must be drained and flushed.
Reassemble the petcock and install it on the fuel tank.