This is the hard to find petcock base gasket for 70's, 80's Kawasaki motorcycles. It goes between the petcock base and the tank. It is equivalent to Part #51039-010. After years, this gasket becomes flat and no longer provides a adequate seal, so when you remove your petcock, you should replace this gasket. This seal is round (O-Ring), but it forms into the groove of your petcock base.

Some applications include:
KZ650 1977-1983
KZ700 1984
KZ750 1980-1983
KZ1000 1981-2005
KZ1100 1982-1983
KZ1300 1979-1982
GPZ750 1982
ZG1000 1986-2006
ZL1000 1987
ZL900 1985-1986
ZN1100 1984-1985
ZN1300 1983-1988
ZX1000 1986-1987
ZX750 (GPZ) 1983-1985
ZX900 NINJA 1984-1986
ZX1000 NINJA 1986-1987

PLEASE READ AND UNDERSTAND DETAILS AND PAYMENT/SHIPPING TERMS BEFORE BUYING. THANKS.