The stringent emissions standard of the EPA’s Tier 4 has caused Yanmar along with all the other diesel engine manufacturers to change their design to be in compliance. The following is a brief explanation of how Yanmar is achieving this with their new design.

The common rail system (CRS) optimizes fuel economy and reduces operating costs.  

High pressure injection atomizes fuel into finer particles which burn more completely.  This results in improved fuel economy, lower cost of operation and less particular matter in emissions.

The electronic control unit (ECU) provides optimum fuel control and accuracy.  

ECU monitors and controls the engine.  It continuously monitors engine conditions and adjusts the fuel delivery accordingly to ensure optimum performance and emissions.

The new engine also comes equipped with an after treatment system, which operates automatically.  The exhaust filter contains a diesel particulate filter (DPF), which captures particulate matter contained in the exhaust gas.

DPF Cleaning

Depending on the load that your tractor is under, as well as temperature, humidity, and engine speed, the DPF may build up with particulate matter, thus requiring cleaning. Filter cleaning is determined by one of three conditions:

  • A prescribed time-based estimation of needed filter cleaning
  • DOC/DPF pressure sensors
  • A particulate matter buildup estimation based on load conditions

Once one of these conditions has been met, filter cleaning will occur.  There are three different types of filter cleaning processes:

  • Passive filter cleaning
  • Active filter cleaning
  • Parked filter cleaning

Passive Filter Cleaning

This process happens automatically When the engine is generating enough heat to oxidize the  particulate matter.  This will occur continuously during normal operation, no tractor icons or symbols will appear on the display.

Active Filter Cleaning

If conditions (temp, load, speed) for passive filter cleaning can not be met, then the PM has to be removed using the Active filter cleaning process.

The exhaust temperature management (ETM) manages the initiation and duration of active filter cleaning.  The ETM system can adjust numerous engine parameters and/or inject a small quantity of fuel into the exhaust stream for a short duration. The fuel then turns to vapor and chemically reacts with the catalysts in the DOC to create heat which then oxidizes the PM.

Like passive filter cleaning, Active filter cleaning requires no user involvement, and it does not interrupt the tractors operation.

Parked Filter Cleaning

In some instances where passive and active filter cleaning have not fully cleaned the PM from the system, a parked filter cleaning will need to take place.  Usually, the only time one of these will need to occur is when your automatic filter cleaning has been disabled for an extended period of time and multiple warnings to engage your filter cleaning were ignored.

The parked filter cleaning process needs to be activated based on usage and operation of the tractor. the process will take approximately 30 min.  See your operator’s manual for more detailed description.

Key features of the Yanmar Diesel Engine:

  • Economical cast-in-block cylinder design for good cooling and long life
  • Direct fuel Injection
    • Improves starting
    • Injects fuel directly on top of pistons for more efficient combustion
    • Develops more horsepower per gallon of fuel than indirect injection engins
  • Aluminum alloy pistons with built-in steel struts are lightweight to reduce connecting rod-bearing loads and provide good heat transfer characteristics.
    • Design permits tighter tolerances and neutralizes expansion of the piston, which reduces blow-by and noise form piston slap
    • Top rings are higher on the piston and a thinner head gasket is used to greatly reduce the volume of unburned waste gases and increase combustion efficiency.
  • Timing gears and injector drive gears have a helical profile to reduce engine noise.
  • Auto-bleed fuel system
    • There is no need to prime the system if the tractor runs out of fuel
    • The system will self-prime the injection pump, lines and injectors, providing fast fuel recovery for easier starting
  • Key start and shutoff eliminates fuel shutoff knob
    • Electric solenoid shuts fuel supply off immediately when key is turned off
  • Water separator
  • See-through coolant recovery tank permits operator to check coolant level without removing radiator cap
    • Sealed radiator compartment keeps trash and debris on outside of hood
  • Dry-type air cleaner with safety element and electronic air service indicator
    • Electronic air restriction indicator alerts operator when air filter servicing is required
    • Dual element design for added engine protection
    • Easy to service
  • Hybrid exhaust
    • Discharges fumes away from the operator and reduces noise from engine
    • Improves operator visibility
    • Optional vertical exhaust kit is available
    • In normal operations, the exhaust goes through the downward exhaust outlet
    • In park regeneration process, the exhaust will go through the upward exhaust outlet

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