CrimpEngine 50HP — Yanmar 4JH2E
Yanmar 4JH2E — 50 HP / 36.8 kW @ 3600 RPM, 4-cyl 1817 cc naturally aspirated (bore 82 × stroke 86 mm). 2.0 kW starter cranks at ~180 A (360 A inrush); 55 A Hitachi internally regulated alternator. Predecessor to the 4JH4 series; common in 35–42 ft cruising sailboats.
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A sizing result with its assumptions attached.
Sized against ABYC E-11. Boats built to UK or EU rules answer to ISO 13297 — check these figures against it before you build. The cranking current is the starter's continuous draw. ABYC E-11 excepts cranking-motor conductors from overcurrent protection, so the fuse shown is the conventional cranking-rated (Class T) choice sized to hold the draw without nuisance tripping — not a wire-protection requirement. The conductor is sized by the Crimp engine for the cranking draw and voltage drop. The 3 m one-way run is a stated reference, not a universal installation prescription.
The part the engine actually sees.
- Continuous draw
- 180 A
- Rated output
- 55 A
- Surge current
- 360 A
Terminal map
| Terminal | Polarity | Direction | Rating |
|---|---|---|---|
| Starter | positive | input | 600 A |
| Alt B+ | positive | output | 200 A |
| Block GND | ground | bidi | 600 A |
What belongs around it.
- 6 m total of 120 mm² (4/0 AWG) marine cable
- Four 120 mm² cable lugs matched to the equipment studs
- 250 A cranking-rated (Class T) fuse at the battery
- Heat-shrink, strain relief, and terminal boots sized to the cable
See what it changes in your system
With JavaScript enabled, describe your existing boat, van, or off-grid system here. The model supplies topology; Crimp's engine computes the attachment, resized runs, checks, and supporting basket.
What is known, assumed, and computed.
Catalog profile
The manufacturer, model, ratings and terminal map are maintained as planning data in Crimp's component catalog. Confirm the current manufacturer manual, exact revision and installed nameplate before ordering or wiring.
Engine reference
Sized against ABYC E-11. Boats built to UK or EU rules answer to ISO 13297 — check these figures against it before you build. The published conductor, fuse and voltage-drop result uses the visible reference length and current basis; it is not a universal installation prescription.
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