We supply the Yanmar 3TNV88 as the replacement for the 3TNV84 in the Kobelco SK50UR - mechanical injection or electronic common rail, new surplus or rebuilt. Same TNV family, one bore size up, and the external components carry across from the engine you are pulling out.
The Kobelco SK50UR is an ultra-short-radius 5-ton class mini excavator built for the tightest urban jobsites, powered by the Yanmar 84 mm-bore 3-cylinder.
ENGINE SPECIFICATION. Three cylinder, four cycle, liquid cooled, vertical in-line. Direct injection, naturally aspirated. Bore and stroke 88 x 90 mm. Displacement 1.642 L (100.2 cu in). Around 36 hp at 3000 rpm at full speed, less in machines governed lower. Dry weight approximately 341 lb (154 kg). Rotation counterclockwise viewed from the flywheel end. Engine as fitted to this machine: Yanmar 3TNV84. Production years: 2000-2010. Rated output in this machine: approximately approx. 33-36 hp.
WHAT WE FIT TO YOUR MACHINE.
On a mini excavator the core engine is only half the job. The bellhousing and flywheel have to mate to your hydraulic pump drive, the oil pan has to clear the undercarriage, and the throttle has to answer to the machine's engine control. Those are all external parts and they carry across from the engine you are pulling out - we build the core to suit.
WHY THE 3TNV88 REPLACES THE 3TNV84.
Yanmar's TNV three-cylinder engines are one family on one architecture - same 90 mm stroke, same block design, same mounting and accessory layout. Only the bore changes: 82 mm (3TNV82A, 1.331 L), 84 mm (3TNV84 and 3TNE84, 1.496 L) and 88 mm (3TNV88 and 3TNE88, 1.642 L). Because the 84 mm and 88 mm engines share the same core and the same mounting layout, the 3TNV88 is the established replacement where an 84 mm engine is no longer available. 3TNE is the earlier generation; 3TNV is the current-production successor.
Before it ships we confirm the mounting points, bellhousing and SAE housing, flywheel, oil pan clearance, PTO and pump drive, throttle linkage and wiring against your machine.
MECHANICAL OR COMMON RAIL - THIS IS THE ONE THING YOU MUST MATCH.
The Yanmar 3TNV88 comes in two fuel systems and they are not interchangeable. MECHANICAL INJECTION uses a mechanical pump and governor, with no ECU or sensors - this is what most machines in the field run, and it is our standard stock. ELECTRONIC COMMON RAIL (HPCR) is ECU-controlled, fitted to machines built to the later emissions standards. We carry both, in new surplus and rebuilt.
The suffix on your data plate - codes like -BKMS, -BPTB2, -QTB - does not mean a different engine. The core is the same across the family: same block, same crank, same 88 x 90 mm bore and stroke, same 1.642 L. The suffix tells you the fuel system and the accessory package. The accessories are external and swap; the fuel system is what has to match.
Two other variants to know about: the 3TNV88F has an ELECTRONIC GOVERNOR with EGR and is a different engine again, and the 3TNV88-GGE is a fixed-speed GENERATOR engine, not a machine engine. There is also a 4-CYLINDER 4TNV88 that is not the same as this three-cylinder engine at all.
Full breakdown of every variant, and how to read your data plate: see our Yanmar 3TNV88 engine buying guide.
WHAT WE NEED FROM YOU.
A photo of the engine data plate - model, suffix, serial - and confirmation that it is going into a Kobelco SK50UR. From that we work out the bore, the cylinder count and the fuel system, tell you what carries across from the old engine, and price you on the right core. Mechanical or common rail, new surplus or rebuilt, we have it.