All of the 7200 to 7700 models use powerful, fuel efficient, high torque, reliable John Deere PowerTech™ diesel engines, designed for agricultural machines and complying with TIER II emission regulations. The 7800 Large-Capacity Self-Propelled Forage Harvester uses a Cummins QSX 15 L engine.

• 7200 - Power at rated speed - 208 kW (283 hp) Maximum power - 230 kW (315 hp)
• 7300 - Power at rated speed - 273 kW (370 hp) Maximum power - 305 kW (415 hp)
• 7400 - Power at rated speed - 323 kW (440 hp) Maximum power - 367 kW (500 hp)
• 7500 - Power at rated speed - 377 kW (513 hp) Maximum power - 420 kW (570 hp)
• 7700 - Power at rated speed - 377 kW (513 hp) Maximum power - 420 kW (570 hp)
• 7800 - Power at rated speed - 441 kW (600 hp) Maximum power - 487 kW (660 hp)

In-line engine mounting provides best visibility to the rear of the machine. Access to the engine and cooling unit is excellent. Cooling air is drawn in from the rear where the least amount of dust and debris is encountered. Torsion to the crankshaft is reduced and a short power band can be used.

• Easier and safer manoeuvring.
• Best engine cooling for reliable operation
• Maintenance and service is easier.
• Good weight balance on both axles for safe transportation and field operation.
• Improved engine reliability.

Maintains correct engine operating temperature, hydraulic and engine oil temperature, fuel temperature and air conditioning heat dissipation in all conditions.

The large diameter air screen is driven by an electric motor whenever the field/ road switch is in field position. A vacuum duct removes dust and crop residues from the screen. When rotary speed drops, a minimum speed indicator warns the operator. The rotary screen opens easily providing access to the whole cooling assembly.

• Ensures ample air supply for optimal cooling capacity.
• Features a brush for active cleaning.
• Keeps cooling assembly clean, requires minimum maintenance.
• Reliable, safe engine operation in all conditions.

The 1020 mm diameter fan moves high volumes of air through the radiator fins to ensure best engine operating temperature under all harvest conditions.

• Ensures ample air supply for best cooling capacity.
• Protects the engine.

The viscous fan drive automatically modulates the cooling fan speed to the cooling air temperature of the engine radiator.

• Functions fully automatic and requires no maintenance.
• Saves fuel in low load and low temperature operating conditions
• Reduces noise level.

Coolant temperature, intake manifold air temperature, and hydrostatic oil temperature are permanently measured. These parameters control the speed of the radiator fan: low or high speed level according to prevailing conditions.

• Adapts radiator fan capacity to cooling requirements.
• Very reliable system for high horsepower engines
• Saves fuel and reduces noise.
• Protects the hydraulic system.

The electronic engine control unit (ECU) controls engine speed and torque and implements engine protection features. Automatic engine speed adjustment feature provides a convenient way to control the engine according to power requirements of the different operations. ECU controls the unit pump injectors and automatically requests appropriate engine speed without any additional operator intervention.

• Relieves the operator of engine adjustments.
• Provides appropriate power to all functions.
• Saves fuel.

Engine speed is automatically limited whenever the system is working in road operating mode and third gear is engaged. In this condition, the automatic engine speed control feature adjusts the engine speed to 1,650 rpm in order to reduce noise level and fuel consumption. A speed sensor on the front axle indicates maximum ground speed and limits engine speed to ensure safe operation.

• Saves fuel and reduces noise level.
• Ensures safe road transport.
• Is fully automatic and reliable.