When you say the FS is the same as the FX except it has the better air cleaner , your not even close. I have and run both and trust me there's a world of difference between the two motors.
I was going by the Kawasaki website, if you compare the FS 22 hp with the FX 22 hp, they have the exact same specs except fot the weight of the bigger air cleaner, about a pound.
here are the specs for both.
Features: FS 22 hp
桧verhead V-valve
?0ï½° V-twin
è±igh performance pressurized lubrication
é«*lectronic spark ignition
柊utomatic compression release
肘nternally vented carburetor with fuel shut-off solenoid
ç´otating grass screen
ç–‹ual element air filter
匹ast-iron cylinder liners
.Specifications
Displacement
726cm3 (44.3cu. in.)
Number of Cylinders
2
Bore x Stroke
3.1 x 3.0 in. (78 x 76mm)
Compression Ratio
8.2:1
Oil capacity
2.2U.S. qt (2.1liters)
Maximum Power
22.0hp (16.4kW)
at 3,600rpm
Maximum Torque
39.4ft lbs (53.5Nï½·m)
at 2,000RPM
Dry weight
91.5lbs (41.5kg)
Features: FX 22 hp
桧verhead v-valve
?0ï½° V-twin
è±igh performance pressurized lubrication
é«*lectronic spark ignition
柊utomatic compression release
ç´otating grass screen
ç–‹ual stage canister air filter
匹ast-iron cylinder liners
ç*†etal engine cover
è±eavy-duty shift-type starter
謬win barrel, internally vented carburetor with fuel shut-off solenoid
.Specifications
Displacement
726cm3 (44.3cu. in.)
Number of Cylinders
2
Bore x Stroke
3.1 x 3.0 in. (78 x 76mm)
Compression Ratio
8.2:1
Oil capacity
2.2U.S. qt (2.1liters)
Maximum Power
22.0hp (16.4kW)
at 3,600rpm
Maximum Torque
39.4ft lbs (53.4Nï½·m)