Engine

Specs

• Yanmar 4JH2E, 50 hp inboard, freshwater-cooled diesel
• Repowered 1998 (current engine)
• Serpentine belt conversion driving the Balmar 120A alternator
• Spare parts aboard: filters, belts, seals, wiring, etc.

Oil

• Capacity (with filter): 4.8 L (5.1 qt)
• Grade: Chevron Delo 400 XLE 15W-40 CK-4 (or any 15W-40 CD or higher)

Raw water pump — separately lubricated (gotcha)

The 4JH2E has two oil fill plugs, both labeled "oil" and physically interchangeable. Don't conflate them:

• Valve cover = main crankcase (the 4.8 L fill above)
• Pump assembly fill = raw water pump gear oil (~100–200 mL). Use vacuum extraction to drain — no drain plug.

The pump fill is a real maintenance item, not optional.

Coolant Drain Ports

For coolant system service (changes, not winterization):

Point	Location
Heat exchanger drain	Port side, front of block below the first pulley (brass petcock)
Engine block drain	??? — service manual says starboard side rear, but not found on this engine
Expansion tank	Remove cap to allow air in while draining

Note: The block drain location is unclear. Yanmar service manuals reference a starboard-side drain at the rear of the block (above crankshaft centerline, aft of oil filter), but this has not been physically confirmed on this engine. Some 4JH2Es may have both drains on the port side, or the block drain may be a hex bolt rather than a petcock.

Fuel