Main Engine 4-Stroke · Main Engines (4-Stroke)
The 12AYM-WET is a 12-cylinder V-type, vertical, water-cooled 4-cycle marine diesel engine with 155x180 mm bore/stroke and 40.76 L displacement, developed as the successor to Yanmar's 12LA/16LA series. It meets IMO Tier II emissions using an internal EGR system and mechanical engine control, without added external EGR hardware. Two duty ratings are offered from the same block: M-rating 1220 kW/1900 rpm for intermittent duty and H-rating 1140 kW/1840 rpm, matched to an MGN924VY marine gearbox.
Every value below comes from the manufacturer datasheet or class-society record on file for this model.
Other models of the same equipment type, Yanmar first.
Free of charge — we forward your request to qualified suppliers for Yanmar equipment from our network of over 114,000 maritime companies.
Tell us what you need for this Yanmar 12AYM-WET — a part, a service call, a second opinion. Are you Yanmar? Claim this brand page.
Service engineer? Write the day report for this 12AYM-WET in OceanSphere Work — photos, hours and parts, as a PDF for the owner. Try it free for 14 days →
Yes. Specifications, documents and service notes for this model are readable without an account. An account adds saved searches and requests, nothing is taken away.
Yes. Tell us the manufacturer, the model and what you need — our desk asks the right suppliers from a network of over 114,000 companies and comes back with a quote or a sourcing plan.
Send us the nameplate or the correct value. We check it against the manufacturer datasheet or class-society record and update the page.