6600 Series KT620

A smooth ride with exceptional power.

Built to last, KOHLER® 6600 Series engines start quickly and reliably with Smart-Choke™ technology. They deliver a consistent cut even in tough mowing conditions. Features a 3 year, unlimited hour, limited warranty.

  • Designed with lower vibration for a more comfortable ride (compared to the 7000 Series engine)
  • Starts hot or cold, even at temperatures below freezing, with Smart-Choke™ technology
  • No need to choke the engine - starts at any throttle position
  • Cleaner cuts - Consistent-Cut™ technology maintains engine speed even in tough mowing conditions
  • Based on Kohler commercial Command PRO® engine design
Owner's manual
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Service manual
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Engine Type

Four-cycle, single-cylinder, air-cooled, vertical shaft, gasoline, OHV, with cast iron liner.

Model KT620
Power[[1]] kw (hp) 15.66(21)
Displacement cm3 (in3) 660 (40.3)
Bore mm (in) 83 (3.3)
Stroke mm (in) 61 (2.4)
Compression Ratio 9.1:1
Dry Weight kg (lbs) 37.2 (82)
Oil Capacity L (US qt) 1.9 (2)
Lubrication Full pressure w/full-flow filter
Dimensions LxWxH mm (in) 473 x 424 x 341
(18.6 x 16.7 x 13.4)
Certified Power[[3]] kw (hp) 15.22 (20.41)
Certified rpm rpm 3600
Emissions Compliance
  • China Phase II
  • CARB Phase III
  • EPA Phase III
  • EU Stage V
Engine Type Consumer

Length is front of air cleaner cover to back of blower housing. Width is side to side. Height is mounting surface to grass screen or air filter.

1 Power (hp) and Torque (ft lbs) specifications for Kohler general purpose engines are rated pursuant to Society of Automotive Engineers (SAE) J1940 based on gross output testing performed according to SAE J1995 without the air cleaner and muffler. Actual engine power and torque are lower and affected by accessories (air cleaner, exhaust, charging, cooling, fuel pump, etc.), application, engine speed, ambient operating conditions (temperature, humidity and altitude) and other factors. This J1940 / J1995 rating provides consistent measurement to customers who may want to control the intake and exhaust features of the engine. For more information, contact Kohler Co. Engine Engineering Department. Kohler Co. reserves the right to change product specifications, designs and standard equipment without notice and without incurring obligation.

2 Inches of H20 @ 3600 RPM WOT

3 J1995 power and torque certified by 3rd Party Witness

Equipment Types

This engine powers the following equipment

  • Residential Riding Mower

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