Piston Std / Kohler 47 874 06-SPack Size:1Gravely 040995, Kohler 47 874 06, Kohler 47 074 16, Kohler 47 874 06-SESF 163-360, Foley/Belsaw 5979373, Foley/PLP 163-360, Green Meadow P360, Laser 94231, NHC 266-8758, Prime Line 7-03815, Rotary 6749, Sunbelt SB-6749Gravely K301 (before Serial No. 1730100013) and M12 (old style); Kohler K301 (before Serial No. 1730100013) and M12 (old style)Ethanol: Not compatible with greater than 10% ethanol fuel, Cylinder Bore Size: 3.375"