OTTO Excavator Parts Ex200 6Bd1T Valve Spring Big 5125610096 512561-0096 5-12561009-6 For Isuzu OTTO Isuzu FSR 6BD1 Valve Spring Big 5125610166 – 100% genuine OEM excavator part, perfect fit for Isuzu 6BD1 engines. Bulk in-stock, fast global shipping. Superior elasticity & fatigue resistance vs aftermarket big springs, cuts rework & returns, boosts resale profits for wholesalers & agents.