Yanmar N18 Valve Spindle
Mega Marine supplies genuine and reconditioned valve spindle for Yanmar N18 marine engines, along with complete engines and a comprehensive range of spare parts. Fast RFQ response and global delivery.
The exhaust valve spindle is the precision-machined alloy steel component that seats against the valve seat insert to seal the exhaust port in 2-stroke marine engines. The seating face is often hard-faced with Stellite or Nimonic overlay for resistance to the highly corrosive and erosive environment of the exhaust gas stream. The spindle rotates slowly during operation to equalise wear and self-clean the seating faces.
Function in the Engine
Seals the exhaust port against combustion gas pressure throughout the compression and expansion strokes, withstands extreme thermal and corrosive loading from exhaust gases, rotates incrementally to self-clean and equalise seat wear.
About the Yanmar N18
Yanmar N-series 180mm bore medium-speed engine for propulsion and auxiliary applications in smaller commercial vessels.
Common Issues Requiring Replacement
Burning and erosion of the seating face from hot gas leakage, guide bore wear causing valve misalignment and uneven seating, hot corrosion from vanadium and sulphur compounds in heavy fuel combustion products, Stellite overlay loss or cracking, fatigue cracking of the valve stem.
Mega Marine supplies genuine OEM and quality reconditioned valve spindle for Yanmar N18 engines, with full traceability and global shipping to any port worldwide. We respond to quote requests within 4–6 hours.
- Engine Brand
- Yanmar
- Engine Model
- N18
- Part Category
- Valve Spindle
- Condition
- Genuine & Reconditioned
Browse the full N18 parts range.
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