Yanmar 4-Stroke 380HP Marine Engine Parts

(1 products)

This page is dedicated to Yanmar 4-Stroke 380HP marine engines and helps you quickly find compatible parts and service information. Below you’ll find maintenance tips, common replacement parts, and troubleshooting guidance. You can also browse the main Yanmar collection for a wider selection of components. Scroll to the bottom of the page to start browsing parts for this engine, and on the collection page use the “Filter & Sort” controls to narrow results by horsepower, year range, and part category.

Browse All Yanmar Parts

How to Identify Your 380HP Model

Locate the engine nameplate/serial plate on the starboard side of the block or rocker cover; note the full model (e.g., 6LY3‑UTP) and serial number.
Read the model suffix: it may indicate the power rating and/or matched marine gear (KMH series) and control type.
LY3-series engines use electronic governing and typically have an ECM and compatible display harness; earlier LY/LY2 mechanical versions lack these—verify before ordering electronics-related parts.
Confirm rated output on the tag (380 mhp at 3300 rpm for the 6LY3‑UTP class) to ensure you select the correct service items.

Platform Overview

Inline‑6 Turbo Diesel (6LY3 Series, ~380 HP)

Feature	Description
Configuration	Inline‑6, 4‑stroke, direct‑injection diesel with turbocharger and seawater‑cooled intercooler; electronic governing (LY3).
Common Models	6LY3‑UTP (~380 mhp), related variants include 6LY3‑STP (440 mhp) and 6LY3‑ETP (480 mhp); many routine service parts are similar—verify by model/serial.
Advantages	Strong power‑to‑weight, compact footprint, efficient fuel delivery, and good mid‑range torque for planing hulls.
Notes	Keep raw‑water pump impeller, anodes, and filters on a regular schedule. Electrical system is typically 12V with high‑output alternator; transmissions are commonly Kanzaki KMH series.

Routine Maintenance & Service Parts

Intervals below are general guidelines; always follow the official Yanmar service manual for your exact model and duty cycle.

Item	Interval*	Remarks	Parts Link
Engine oil + oil filter	Every 100 hrs or annually	Use marine‑grade diesel oil meeting spec; replace filter at every oil change.	Yanmar Oil filters
Primary/secondary fuel filters	Every 100 hrs or as needed	Replace both elements; drain water separator frequently in high‑moisture environments.	Yanmar Fuel filters
Raw‑water pump impeller	200 hrs or annually	Inspect for vane set and cracking; renew gasket/O‑ring during service.	Impellers
Heat‑exchanger/anode zincs	Inspect 50 hrs; replace as needed	Shorten interval in warm/salt/brackish water; check for debris and scaling.	Anodes
Air filter	Inspect 100 hrs; replace as needed	Restricted intake raises EGT/soot and reduces boost.	Yanmar Air filters
Drive belts (alt./water pump)	Inspect 100 hrs; replace 1–2 yrs	Check tension and glazing; carry spares onboard.	Belt
Closed‑loop coolant	Every 2 years (typ.)	Use the correct coolant type; flush system per manual.	Yanmar
Marine gear/transmission oil	100–250 hrs (duty‑dependent)	Follow the KMH gearbox spec and interval; check for clutch debris.	Yanmar Service & Maintenance Kits
Exhaust mixing elbow	Inspect 2–3 years	Check for corrosion, restriction, or leaks that can cause steam/overheat.	Yanmar Elbows

Common Symptoms & Quick Checks

Symptom	Check First	Related Parts
High temperature alarm / steam from exhaust	Sea strainer and intake screen, raw‑water pump impeller, belt tension, coolant level, thermostat, exchanger scaling.	Water pump impeller kit, belts, anodes, thermostat, cleaning kits.
Poor acceleration or cannot reach rated RPM	Primary/secondary fuel filters, air filter restriction, boost leaks, hull/prop fouling, ECM faults.	Fuel filter elements, air filter, turbo hoses, turbocharger.
Hard starting / stalls after start	Battery voltage and cranking speed, starter draw, fuel supply/priming, air in fuel, injector condition.	Starter, fuel filter, injectors, fuel hoses and clamps.
Excessive black smoke under load	Over‑prop or hull growth, restricted air filter, turbo/wastegate issue, injector spray pattern.	Air filter, turbocharger, boost hoses, injectors.
Saltwater drips or soot at mixing elbow	Inspect elbow for corrosion/cracks, gasket condition, raw‑water flow rate.	Exhaust elbow, elbow gasket, water pump impeller kit.

FAQs

Are parts interchangeable across different LY/LY3 ratings and years?

Many routine items (filters, belts, anodes, impellers) are shared across LY3 variants, but electronics, hoses, and exhaust components can differ. Always confirm with the full model and serial number before ordering.

When should I replace the raw‑water impeller?

As a preventative measure, replace annually or every ~200 hours (whichever comes first). Shorten the interval if the engine sees heavy duty, sandy/silty water, or marginal intake conditions.

How often should marine gearbox oil be changed?

Intervals vary by gearbox model and duty cycle. A common guideline is 100–250 hours or annually; follow the KMH gearbox manual and always use the specified oil type/viscosity.

What information do you need to verify part compatibility?

Please provide the full engine model (e.g., 6LY3‑UTP), serial number, gearbox model, and clear photos of the nameplate and the part you’re replacing.

Ready to find parts by horsepower, year, and model? Browse the main Yanmar collection to get started.

Shop Yanmar Parts

If you’re unsure about your model, send us a photo of the nameplate and the part you need and we’ll help verify compatibility.