Kubota KX121-2

Browse aftermarket replacement parts for the Kubota KX121-2 mini excavator. Second generation Kubota K Series 4-ton conventional tail swing mini excavator, the predecessor to the KX121-3 that replaced it in the early 2000s.

Use filters or search by OEM part number to find the right part. Compatibility details are listed on each product page.

Parts Compatible with the Kubota KX121-2 Mini Excavator

The KX121-2 is the second generation 4 ton class entry in Kubota's K Series mini excavator family, produced from the late 1990s through the early 2000s before being replaced by the KX121-3 third generation. The KX121-2 is the larger displacement counterpart to the KX91-2 in the same era, using the V1505 era 4-cylinder mechanical injection diesel engine and direct-drive hydraulic main pump. Customers commonly find KX121-2 machines still in fleet service in landscaping, utility, and general construction applications.

The KX121-2 shares many service parts with the KX161-2 (the 5 ton sibling) and with the KX101 (the 3.5 ton sibling) because Kubota engineered the second generation K Series 4-cylinder line on a shared parts platform with the V1505 era engine family. Successor KX121-3 service parts generally do not cross because the KX121-3 introduced a different engine cooling and fuel filter package along with a refreshed cab.

Common Replacement Parts for the Kubota KX121-2

Engine service uses Fuel Filter 15831-43380 as the primary fuel filter for the V1505 era engine. Oil Switch 15531-39010 covers the oil pressure monitoring across the V1505 K Series mini excavator family.

Cooling system service uses Water Pump 15521-73030, Water Pump Gasket 15521-73430, and Thermostat 19434-73010, which together cover the most common cooling system service items as these machines approach the end of their second or third water pump service cycle. Top-end service hardware includes Stud 01513-50822, Hex Nut 02012-60060, and Gasket 15841-53620. Many of these internal engine and cooling parts cross to the KX161-2 and KX101 (late-90s K Series 4-cylinder siblings) and to other Kubota equipment powered by the same V1505 4-cylinder engine family.