Yamaha YA2-28158-03-03 - Main Bearing (U-S 0.50MM) is a genuine Yamaha part. This engine part is one of the internal components that keep the engine running as designed. Match part number YA2-28158-03-03 to the Yamaha parts diagram for your model to confirm it is the component you need.

---

Key Features & Benefits

• Installs in the position shown in the Yamaha engine parts diagram.
• Built to Yamaha's specification for its engine location.
• Replaces worn, scored, or damaged engine components.
• Size designation U-S 0.50MM as listed by Yamaha; confirm the required size with service manual measurements.
• Sold under Yamaha part number YA2-28158-03-03.

---

Frequently Asked Questions

What is the Yamaha Main Bearing (U-S 0.50MM) (YA2-28158-03-03)?

The Main Bearing (U-S 0.50MM) is a genuine Yamaha part sold under part number YA2-28158-03-03. It replaces a worn or damaged engine component with the specified Yamaha part.

What does the U-S 0.50MM size on part YA2-28158-03-03 mean?

O-S marks an oversize part and U-S an undersize part. Yamaha lists YA2-28158-03-03 as U-S 0.50MM, which is used when the mating part has been machined or worn to match. Measure and confirm the required size using the Yamaha service manual.

Should related parts be replaced with the Main Bearing (U-S 0.50MM), part YA2-28158-03-03?

When replacing engine internals, inspect mating parts and replace gaskets and seals disturbed during disassembly. Refer to the Yamaha service manual for your model when installing YA2-28158-03-03.

---

WARNING: This product can expose you to chemicals which are known to the State of California to cause cancer, birth defects or other reproductive harm. For more information go to P65Warnings.ca.gov.