Kawasaki FR651V

Kawasaki FR651VThe Kawasaki FR651V is a 0.73 l (726 cc, 44.3 cu-in) V-twin 90° air-cooled 4-stroke internal combustion small gasoline engine with vertical shaft, manufactured by Kawasaki Heavy Industries LTd., for general-purpose applications, such as residential zero-turn mowers, lawn and garden tractors.

The FR651V has 90 degrees V-twin design with vertical PTO shaft, overhead valves, cast iron cylinder liners, and spherical combustion chamber, rotating metal grass chopper screen. The engine is equipped with the electronic spark ignition system and internally vented carburetor with fuel shut-off solenoid. The motor uses a high-performance lubrication system and single-stage air filter.

The engine has an automatic compression release (ACR) system with bendix type starter. 13A or 20A charge coils are available as an option.

It has a 78.0 mm (3.07 in) cylinder bore and 76.0 mm (2.99 in) piston stroke. Compression ratio rating is 8.2:1. The Kawasaki FR651V produced 19.2 PS (14.1 kW; 18.8 HP) at 3,600 rpm or 21.8 PS (16.0 kW; 21.5 HP) at 3,600 rpm of maximum horsepower and 53.2 Nm (5.43 kg·m; 39.26 ft·lb) at 1,800 rpm or 53.3 Nm (5.44 kg·m; 39.34 ft·lb) at 2,200 rpm of torque.

General information

Engine Specifications
Type4-stroke, OHV, V-twin 90°
Displacement726 cm 3 (44.3 cu-in)
Max. horsepower 19.2 PS (14.1 KW; 18.8 HP) at 3,600 rpm
21.8 PS (16.0 KW; 21.5 HP) at 3,600 rpm
Max. torque (crank PTO) 53.2 Nm (5.43 kg·m; 39.26 ft·lb) at 1,800 rpm
53.3 Nm (5.44 kg·m; 39.34 ft·lb) at 2,200 rpm
CarburetorInternally vented with fuel shut-off solenoid
Cooling systemAir-cooling
Ignition systemElectronic spark ignition
Lubricating systemFull pressure with spin-on oil filter
Starting systemBendix type starter
Charging system13A or 20A charge coil (option)
Fuel usedUnleaded gasoline (octane number 86 or higher)
Fuel consumption245 g/HPh
Cooling systemPressurized forced circulation type

Dimensions and Weight

Kawasaki FR651V
Length, mm (in)501 (19.7)
Width, mm (in)466 (18.3)
Height, mm (in)392 (15.4)
Dry weight, kg (lb)40.0 (88.2)

Tightening torque specs

Tightening torque specs
Cylinder head46 Nm; 4.6 kg·m; 33.9 ft·lb
Connecting rod10 Nm; 1.0 kg·m; 7.4 ft·lb
Flywheel56 Nm; 5.7 kg·m; 41.3 ft·lb
Crankcase cover27.5 Nm; 2.75 kg·m; 20.3 ft·lb
Intake manifold9 Nm; 0.9 kg·m; 6.6 ft·lb
Oil drain plug7 Nm; 0.7 kg·m; 5.2 ft·lb
Valve clearance lock nut11 Nm; 1.1 kg·m; 8.1 ft·lb

Maintenance data

Maximum speed3500 ± 100 rpm
Idle speed1500 ± 100 rpm
Cylinder compression4.5 kg/cm2 (64 psi) at 500 rpm
Valve clearance
Intake valve0.10-0.15 mm (0.004-0.006 in)
Exhaust valve0.10-0.15 mm (0.004-0.006 in)
Oil system
Oil type4-stroke or an equivalent (SJ or higher class)
Recommended oilSAE 10W-40, 10W-30
Oil capacity (with filter changed) With oil filter: 2.1 litre
Without oil filter: 1.8 litre
Ignition system
Spark plugNGK: BPR4ES
Spark plug gap0.7-0.8 mm (0.027-0.031 in)
Ignition coil air gap0.2-0.4 mm (0.008-0.011 in)
Spark plug tightening torque22 Nm; 2.2 kg·m; 16.2 ft·lb
Author: Sergei Wers
About: Co-founder and CEO of a multi-brand auto repair shop (engine repair, chassis repair, body repair and painting) for over 15 years. I have been developing internet sites with technical specifications for more than seven years.

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We try to use verified sources and official documentation, however, differences between sources or errors in entering information may occur. We do not provide advice on technical issues related to the engines operation or repair. We do not recommend using provided information for engines repairing engines or spare parts ordering, use only official service manuals and spare-parts catalogs.


  1. If this motor has automatic compression release ,how can you check cylinder compression?
    I’ve checked it , and have 30 lbs left cylinder 90 lbs right cylinder

  2. please all I want to know is how much oil I should put in a Kawasaki 21.5 hp fr651v engine ?????????? one little question

  3. New mower FS 651v 5hrs use started smoking blue smoke on start up . Engine replaced problem now occurring again. Smokes on start any suggestions appreciated .

    • When I made the first oil change only about 1 1/3 quart came out. I removed the filter and let the oil drain for about ten minutes. I installed the new filter, added two quarts of fresh oil and started the engine. It immediately started to blow blue smoke. I shut off the engine and checked the oil level that showed it was well above the full line. I drained out close to half a quart and the dipstick showed it was right at the full mark. I then mowed the lawn and rechecked the oil when finished. It was exactly at the full mark. If this engine takes 2.1 liters of oil it must hide it somewhere.

      • Good advice! you are correct. If you are married, it has been a long time since you heard those words addressed to you.

  4. i have the same problems these people are talking about mine got worse back and fourth to dealer , first blow head gasket at 20 Hours got it back not enough compression, burning oil , it misfire back fire back to dealer could not find anything wrong but something was wrong so they changed a bunch of parts they called me said come in and i did went to back it was still same but worse. He said we put the best mechanics on this and nothing works but found the problem and it can be fixed with new engine cam shaft was bent was one, where the cam sets down into the hole ,he gave a a name ,was broken , not fixable , that two and governor clips are sheared inside the motor . since it was under warranty and under low hours money back or new zero turn mower , i got my money back owner said he would do the same so that saying a lot about these engines

  5. The oil stem loosens. You need to unscrew the mounting bracket, locate the separation, and use RTV silicon very carefully to seal the oil stem. You are getting smoking because oil is leaking from this location and dripping onto the exhaust.

  6. You are right! Good advice given. If you are married, I bet it has been a long time since you heard those words.

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