Aftermarket Seadoo 657 657 X 717 Carburetor Base Gasket 290850373 GTX Gs GTI Seadoo 657 657 X 717 Carburetor base gasket Aftermarket part that fits OEM # 290850373 ITEM DESCRIPTION New aftermarket carburetor base gasket. Includes ONE (1) Carburetor base gasket as pictured. It replaces the following SeaDoo part numbers: 293250134 293250070 290850373 420850373 293250042 270000114 GK-290850373 290850373 293250070 293250042 270000114