... 2-strocke, 4 stroke, Pumps PISTON RINGModelNameDimension6DCOMPRESSION50.82 × 1.58 × 2.08 std,020OIL50.82 × 2.36 ... 2.36 × 3.08 std,020 4R 2 1/2 ″COMPRESSION63.50 × 1.58 × 2.88 std,020,030OIL63. ... 16 × 2.88 std,020,030 4R 2 11/16 ″COMPRESSION68.26 × 1.58 × 3.08 std,020, ... 030OIL68.26 × 3.16 × 3.08 std,020,030 4R 2 ... 15/16 ″COMPRESSION74.61 × 1.58 × 3.08 std,020 ...