Engine Kit, GX390, 414cc, +.160 Honda Crank, 88mm Cast Flat-Top Our Price: $485.00 Engine Kit, GX390, 420cc , +.200 Cast Crank, 88mm Cast Flat-Top Our Price: $321.00 Gasket Kit/Engine Set, GX120 UT2: Genuine Honda Our Price: $31.29 Hop Up Kit; GX240, GX270, 9hp OHV; Stage 4 Our Price: $886.00 Engine Kit, 180cc, GX160 + .160", Stroker Kit Our Price: $297.00 Hop Up Kit, 224cc Predator, Stage 3 Our Price: $331.00