Yamaha 7X9-11635-01-00 - Piston (1ST O-S) is a genuine Yamaha part. This engine part is one of the internal components that keep the engine running as designed. Match part number 7X9-11635-01-00 to the Yamaha parts diagram for your model to confirm it is the component you need.

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Key Features & Benefits

• Built to Yamaha's specification for its engine location.
• Replaces worn, scored, or damaged engine components.
• Installs in the position shown in the Yamaha engine parts diagram.
• Size designation 1ST O-S as listed by Yamaha; confirm the required size with service manual measurements.

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Frequently Asked Questions

What is Yamaha part 7X9-11635-01-00?

7X9-11635-01-00 is the Yamaha part number for the Piston (1ST O-S), a genuine Yamaha part. It replaces a worn or damaged engine component with the specified Yamaha part.

What does the 1ST O-S size on part 7X9-11635-01-00 mean?

O-S marks an oversize part and U-S an undersize part. Yamaha lists 7X9-11635-01-00 as 1ST O-S, 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.

Where does the Piston (1ST O-S), part 7X9-11635-01-00, fit in the engine?

The Piston (1ST O-S) installs in the engine location shown for part 7X9-11635-01-00 in the Yamaha parts diagram for your model.

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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.