Welcome to the world of Yanmar Marine!
Yanmar Marine offers engines, drive systems and accessories for all types of boats, from runabouts to sailboats, and from cruisers to mega yachts. In marine leisure boating, the worldwide reputation of Yanmar Marine is second to none. We design our engines to respect nature. This means quieter engines, with minimal vibrations, cleaner than ever. All of our engines meet applicable regulations, including emissions, at the time of manufacture.
To help you enjoy your Yanmar JH4 series engine for many years to come, please follow these recommendations:
- Read and understand this Operation Manual before you operate the machine to ensure that you follow safe operating practices and maintenance procedures.
- Keep this Operation Manual in a convenient place for easy access.
- If this Operation Manual is lost or damaged, order a new one from your authorized Yanmar marine dealer or distributor.
- Make sure this manual is transferred to subsequent owners. This manual should be considered a permanent part of the engine and remain with it.
- Constant efforts are made to improve the quality and performance of Yanmar products, so some details included in this Operation Manual may differ slightly from your engine. If you have any questions about these differences, please contact your authorized Yanmar marine dealer or distributor.
- The specifications and components (instrument panel, fuel tank, etc.) described in this manual may differ from ones installed on your vessel. Please refer to the manual provided by the manufacturer of these components.
If you have an installation with two or three engines, and only one engine is operating, please note that if the propeller shaft thru hull (stuffing box) is lubricated by engine water pressure and the engines are interconnected, care must be taken that water from the running engine does not enter the exhaust of the non-running engine (s). This water could cause seizure of the non-running engine(s). See your authorized Yanmar marine dealer or distributor for a complete explanation of this condition.
YANMAR JH4 FEATURES AND APPLICATIONS
- The JH4 series are four-stroke direct injection diesel engines equipped with liquid coolant systems.
- The 3JH4E is 3-cylinder and naturally aspirated.
- The 4JH4AE is 4-cylinder and naturally aspirated.
- The 4JH4–TE is 4-cylinder and turbocharged.
- The 4JH4–HTE is 4-cylinder and turbocharged with an intercooler.
- The engines are equipped with a marine gear or sail drive unit.
It is recommended that new vessels be propped so the engines can operate at 100 - 200 rpm above the fuel stop power rpm to allow for some added weight and hull resistance.
The engine must be installed correctly with coolant lines, exhaust gas lines and electrical wiring. Any auxiliary equipment attached to the engine should be easy to use and accessible for service. To handle the drive equipment, propulsion systems (including the propeller) and other onboard equipment, always observe the instructions and cautions given in the operation manuals supplied by the shipyard and equipment manufacturers.
The JH4 series engines are designed to be operated at maximum throttle (3000 - 3200 rpm) for less than 5% of total engine time (30 minutes out of every 10 hours) and cruising speed (2800 rpm or less) for less than 90% of total engine time (9 hours out of every 10 hours).
New Engine Break-In
As with all reciprocating engines, the way your engine is operated during its first 50 hours of operation plays a very significant role in determining how long it will last and how well the engine will perform over its lifetime.
A new Yanmar diesel engine must be operated at suitable speeds and power settings during the break in period to make the sliding parts, such as piston rings, break in properly and to stabilize engine combustion.