Yanmar 3YM20 parts
The Yanmar 3YM20 is a compact three-cylinder engine installed in many sailing yachts and smaller motorboats. Here you’ll find parts for regular servicing and for repairs to the cooling, fuel, exhaust and electrical systems.
Looking for another YM engine? View all our
Yanmar YM Series parts, including parts for the 2YM15 and 3YM30.
Servicing your Yanmar 3YM20
Parts commonly replaced during maintenance include:
- Oil and fuel filters
- Seawater-pump impellers
- Alternator and pump belts
- Air filters and anodes
- Gaskets and seals
- Service kits
For larger jobs, you’ll also find circulation pumps, seawater-pump parts, thermostats, sensors, exhaust elbows, starter motors, alternators and engine mounts.
Our range includes genuine Yanmar parts and good aftermarket alternatives. The manufacturer and condition are shown on each product page.
Cooling and drive belts
The 3YM20 uses both seawater and freshwater circuits to keep the engine at the correct temperature. A worn impeller, blocked seawater intake or damaged pump part can reduce the cooling-water flow and cause overheating.
Check the impeller, belts, hoses and coolant level during servicing. Replace a belt if it is cracked, worn or no longer tensions correctly.
Several service parts are shared with the
Yanmar 3YM30, but always compare the listed engine compatibility and part number.
Check the part number
Before ordering, check the complete engine model and serial number on the identification plate. Compare the original Yanmar part number with the number shown on the product page.
If you’re unsure, send us the engine details and any number shown on the old part. A clear photo can help us check the correct replacement.
