HIPA 503 28 15-04 Carburetor for Husqvarna 51 55 Chainsaw # WT-170 Replacement manufacturer part number: 503 28 15-04, WT-170 For Husqvarna 51 and 55 Chainsaws, 01 - 1990 For Husqvarna 51 and 55 Chainsaws, 06 - 1994