45 mhp of Common-Rail Power for Saildrive and Shaft Installations
The YANMAR 4JH45 is a 2.190 L, four-cylinder marine diesel rated at 33.1 kW / 45 mhp at 3000 rpm, the second step in the JH-CR series, which covers 40 to 110 mhp in five output models. The JH-CR series sets the global standard in sailboat and small craft propulsion, for sailboats, smaller motorboats and light-duty commercial vessels. Built on YANMAR’s long-established TNV industrial block with a custom-built Bosch common-rail fuel injection system, it brings common-rail technology to sailboats and smaller craft, and its footprint, similar to previous models, makes it an ideal choice for repowers. YANMAR built the series around five things: clean, interconnective, quiet, powerful and fuel efficient.
Powerful and fuel efficient. Bosch common-rail direct injection gives a compact design with impressive power output, with fuel consumption optimized for longer journeys. YANMAR offers four power ratings across the one 4JH-CR design, to fit a wide variety of boat sizes and applications.
Clean and quiet. The 4JH45 meets EPA Tier 3 and EU RCD 2 and produces minimal emissions thanks to its advanced common-rail technology, and is engineered for minimal noise and smooth operation.
Interconnective. Seamless integration with marine electronics and systems: mechanical controls come as standard, with the option to upgrade to electronic control through the YANMAR VC20 or VC10 vessel control systems, the JC20A joystick for twin shaft-drive installations, and the YD42 and YD25 displays. The 4JH45 is offered with the YANMAR SD60 saildrive or, for shaft drive, with Kanzaki KM35P, KM35A2 and KM4A1 or ZF30M gears. It is certified for recreational and light-duty commercial applications and is USCG lifeboat approved, with a SOLAS option.
- Powerful: 33.1 kW / 45 mhp at 3000 rpm, compact design with impressive power output
- Fuel efficient: Bosch common-rail injection optimized for fuel consumption on longer journeys
- Clean: meets EPA Tier 3 and EU RCD 2, minimal emissions
- Quiet: engineered for minimal noise and smooth operation
- Interconnective: mechanical controls standard; VC20 or VC10 vessel control system optional
- SD60 saildrive or shaft drive with Kanzaki or ZF gears, 220 kg / 485 lb dry weight without gear
SD60 saildrive
YANMAR designed and developed the SD60 saildrive to match its 3JH40, 4JH45, 4JH57 and 4JH80 engines, with two bell housing sizes to cover the range. It connects directly to the engine’s dedicated marine housing without adapters or couplings, which keeps the propulsion system compact and reduces rotational mass and vibration, and its oil can be changed without hauling the boat out.
| Specification |
Value |
| Type |
Saildrive |
| Clutch |
Mechanical multi-disc |
| Reduction ratios |
2.23, 2.49 |
| Dry weight |
44 kg / 97 lb |
Shaft drive gears
For shaft-drive installations the 4JH45 is supplied with the marine gears below. The Kanzaki gears use a mechanical cone clutch and the ZF30M a mechanical multi-disc clutch. Other marine gearboxes and configurations are available on request; ask Mastry for the right match to your hull.
| Gear |
Type |
Reduction ratios |
Gear dry weight |
| Kanzaki KM35P |
Parallel |
2.36, 2.61 |
15 kg / 33 lb |
| Kanzaki KM35A2 |
7 degree down angle |
2.33, 2.64 |
16 kg / 35 lb |
| Kanzaki KM4A1 |
7 degree down angle |
1.47, 2.14, 2.63 |
33 kg / 73 lb |
| ZF30M |
Parallel |
2.15, 2.70 |
23 kg / 51 lb |
VC20 vessel control system
YANMAR’s second-generation vessel control system for all electronically managed YANMAR engines. A J1939-based CAN-bus system with dedicated engine networks, a standard emergency back-up panel and NMEA connections for other onboard systems. Controls every engine and transmission function and displays engine alarms and diagnostic codes.
VC10 vessel control system
YANMAR’s vessel control system for electronically managed YANMAR engines. A J1939-based CAN-bus system with a dedicated network to each engine, a standard emergency back-up panel and built-in NMEA connections for other onboard systems. Supplied with controls, full-color digital displays with NMEA2000 or J1939 gauge output, and all cabling; controls every engine and transmission function and displays engine alarms and diagnostic codes.
JC20A joystick, shaft drive
Inboard joystick control system for twin shaft-drive YANMAR common-rail engines, for powerboats and catamarans alike, in new installations or retrofit. Engages the bow thruster and adjusts engine speed for easy docking and maneuvering in tight waterways or marinas, with accurate, responsive and intuitive control.
YD42 display
Compact full-color multi-function display in modern glass styling. Shows engine speed, load, oil pressure and coolant temperature alongside wind, speed, depth and AIS data, and reads YANMAR engine alarm and diagnostic codes.
YD25 panel
Compact switch panel with a 2.5 inch LCD showing all YANMAR engine data, alarms and diagnostic codes. Integrates with multifunction displays and glass helms, or serves as a standalone instrument on smaller vessels.
B25 and C35 panels
Start/stop tachometer panels for JH-CR and 4LV engines. The B25 carries a tachometer only; the C35 adds water temperature and oil pressure gauges. Both show engine hours, battery voltage, throttle position, engine load, fuel rate, intake air pressure and fuel temperature.
