Description
Petcock Sealing Washer — Creates a leak-proof seal between the fuel petcock (fuel tap valve) and the gas tank mounting threads to prevent fuel seepage.
Bonded rubber (Buna-N) Dowty/Stat-O-Seal type washer with steel or zinc-plated steel backing; 12.7mm (0.500 in) ID, 22.4mm (0.880 in) OD; fits 1/4-inch BSP (British Standard Pipe) threaded petcock applications — OEM ref: 70-7351, 70-6961, 82-8198, 065329, E7351
Fitment
| Triumph | Post-war models with 1/4-inch BSP petcocks including T20 Tiger Cub, T100 Tiger, T120 Bonneville, TR6 Trophy, T140, T150 Trident, and most 200cc, 500cc, 650cc, 750cc singles and twins | 1940s–1980s |
| Norton | Commando and most models with 1/4-inch BSP petcocks | 1960s–1980s |
| BSA | A65 Lightning, A65 Thunderbolt, A50, Rocket III, and other triples and twins with 1/4-inch BSP threads (or retrofitted with Triumph petcocks) | 1969-on triples, 1971-on twins |
Two required per bike (one per petcock)
Used with flat washer 83-0002 or 83-0003. Installation order: steel flat washer on petcock threads first, then Dowty seal on top so rubber seal faces tank. Not suitable for earlier BSA models with larger 3/8-inch BSP fittings. Apply light lubricant (P80, Vaseline, or oil) to rubber seal before installation to prevent damage from sharp threads. Modern ethanol fuels may degrade rubber over time.
