6S5-12121-00-00 Exhaust Valve for Yamaha 252S 1900 2024-2026

Exhaust Valve for Yamaha

This exhaust valve, part number 6S5-12121-00-00, controls exhaust gas flow from the combustion chamber to the exhaust port, and it is a direct-fit replacement component for Yamaha marine engines.

Overview

This exhaust valve is a critical engine component that seals and releases exhaust gases during the combustion cycle. Built to OEM specifications and carrying the 6S5-12121-00-00 part number, it delivers reliable sealing and heat resistance for Yamaha marine engines. It suits boat owners and marine mechanics performing top-end rebuilds or routine valve service.

Built For Performance

• Precision-ground valve face for a tight seal against the valve seat
• Heat-resistant alloy construction withstands high exhaust temperatures
• Chrome-plated stem reduces friction and wear in the valve guide
• Direct cross-reference to OEM part number 6S5-12121-00-00
• Hardened tip resists mushrooming from rocker arm contact
• Manufactured to factory dimensions for drop-in fitment

Fits These Machines

• for Yamaha 252S 1900 (2024-2026)

On-The-Job Use

• Top-end engine rebuilds on Yamaha 252S 1900 boats
• Routine valve inspection and replacement during service intervals
• Marine engine repair shops handling Yamaha jet boat powerplants
• Restoring compression and exhaust flow after valve burnout

Specs At A Glance

Good To Know

Q: Should exhaust valves be replaced in sets? A: Replacing all valves in the affected cylinder head at once is common practice, since wear tends to be even across the set. Check valve guides and seats at the same time for best results.

Q: Does this valve require lapping after installation? A: Verify seat contact and adjust valve clearance to factory specification after installation. Lapping may be needed if the seat shows any pitting or uneven wear.

Slight variation in finish or dimensions may occur between production runs, and fit can depend on serial number, so confirm compatibility before ordering.