6S5-12121-00-00 Exhaust Valve for Yamaha GP 1800 2017-2018

Exhaust Valve for Yamaha

This exhaust valve (OEM cross-reference 6S5-12121-00-00) regulates exhaust gas flow in the engine, opening and sealing at the correct moment to maintain combustion efficiency and power output.

Overview

This exhaust valve is a replacement component for the listed Yamaha watercraft, identified by OEM cross-reference 6S5-12121-00-00. It restores proper sealing in the exhaust path so the engine runs cleanly and holds compression. This exhaust valve is aimed at owners servicing the GP 1800 platform.

Built For Performance

• OEM cross-reference 6S5-12121-00-00 for easy matching
• Engineered to withstand high marine exhaust temperatures
• Precision-formed head and stem for consistent sealing
• Reliable seat contact that supports steady compression
• Heat-resistant alloy construction for continuous operation

Fits These Machines

• for Yamaha GP 1800, 2017-2018

On-The-Job Use

• Top-end rebuilds on the GP 1800 engine
• Replacing a burnt or leaking exhaust valve
• Routine valve service and clearance adjustment
• Restoring compression on a high-hour watercraft

Specs At A Glance

Good To Know

Q: Does this replace the factory Yamaha valve? A: It is an aftermarket exhaust valve that cross-references OEM number 6S5-12121-00-00, so it is not an original brand item. Verify your model and serial number before ordering.

Q: How many should I order? A: The amount you need depends on how many exhaust valves your engine uses and which are being replaced. Check your service manual or inspect the engine before purchase.

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