4TNV94 Flywheel Gear YM129900-21600 for Yanmar Engine Parts

Product Details

Product Overview

This is a high-precision Flywheel Gear specifically designed for the Yanmar 4TNV94 diesel engine. The part carries the OEM reference number YM129900-21600 (also listed as 129900-21600), ensuring a direct replacement for the original component. As a critical part of the engine’s starting and timing system, this flywheel gear is essential for reliable operation in demanding environments.

Sourced from, a reputable supplier based in Guangdong, China, this component is manufactured to meet original equipment (OEM) size specifications. It is commonly used in a wide range of heavy-duty applications, including construction machinery, agricultural tractors, industrial power units, marine propulsion systems, and generator sets.

Key Features & Benefits

• Precise OEM Fitment: Manufactured to the exact OEM size and specifications (YM129900-21600) to guarantee a seamless, direct replacement for your Yanmar 4TNV94 engine without modification.
• Durable Construction: Built from high-grade materials to withstand the high torque and cyclic stress of diesel engine operation, ensuring long service life and resistance to wear.
• Stringent Quality Control: Each unit undergoes a machinery test report and video outgoing inspection to verify dimensional accuracy and structural integrity before shipment.
• Versatile Application: Designed for the robust 4TNV94 engine platform, making it suitable for a diverse range of equipment from excavators and loaders to marine vessels and backup generators.
• Reliable Performance: Essential for proper starter motor engagement and engine timing, this gear ensures smooth starts and stable engine operation under heavy loads.

Technical Specifications

OEM Cross-Reference

This flywheel gear is a direct replacement for the following genuine Yanmar part numbers:

• YM129900-21600 (Primary OEM Number)
• 129900-21600 (Alternate Numbering Format)

Note: Always verify your existing part number before purchase to ensure compatibility.

Compatibility

This component is specifically designed for the Yanmar 4TNV94 diesel engine. Due to the widespread use of this engine platform, this gear is commonly used for the following types of equipment:

• Construction Machinery: Mini excavators, compact loaders, and skid steers.
• Agricultural Equipment: Tractors, harvesters, and tillers.
• Industrial Applications: Air compressors, pumps, and welding units.
• Marine & Power Generation: Auxiliary engines for boats and standby generator sets.

Please confirm your specific engine model and equipment requirements before ordering.

Global Supply & Distribution

offers worldwide shipping and serves a global network of B2B clients, including parts distributors, workshops, and equipment dealers. We maintain a consistent stock of Yanmar engine components to ensure fast delivery to major markets:

• North America: Los Angeles, Houston, Toronto
• Europe: Rotterdam, Hamburg, Antwerp
• Asia-Pacific: Singapore, Sydney, Dubai
• Middle East & Africa: Jebel Ali, Durban, Lagos

We have extensive export experience and ensure that all shipments comply with international trade regulations. Drop-shipping and bulk order options are available for qualified buyers.

Quality Assurance

• Manufacturing Standards: Produced in ISO-certified facilities with strict adherence to OEM tolerances.
• Testing: A Machinery Test Report is provided with each shipment to confirm dimensional and material integrity.
• Inspection:Video Outgoing Inspection is available upon request to provide visual confirmation of the product before shipping.
• Warranty: Backed by a 6-month warranty against manufacturing defects. After-warranty service includes Online Support for technical inquiries.

FAQ

Q: Is this flywheel gear an exact OEM replacement for the Yanmar 4TNV94?
A: Yes, this part is manufactured to the exact OEM specifications of the Yanmar part number YM129900-21600. It is designed as a direct drop-in replacement for the 4TNV94 engine, requiring no additional modifications for installation.

Q: How should I install this flywheel gear?
A: Installation should be performed by a qualified diesel mechanic. The process typically involves removing the transmission or bell housing, securing the flywheel in place, removing the old gear (which may require a press or puller), and pressing the new gear onto the flywheel. Always consult your engine’s service manual for the correct torque specifications and installation procedures.

Q: What maintenance is required for the flywheel gear?
A: The flywheel gear itself is a low-maintenance component. However, regular inspection of the starter motor drive gear and the ring gear teeth for wear, chipping, or damage is recommended during routine engine service. Proper starter motor alignment and ensuring the engine is not started under excessive load will maximize the lifespan of the gear.