Page 120 of 394
5-13
EBU01234
Engine oil/transfer gear oil 
Make sure the engine oil/transfer gear oil is at the
specified level. Add oil as necessary. (See pages
8-13–8-25.)
Recommended oil:
Recommended engine oil classification:
API Service SE, SF, SG type or higher
-20˚ -10˚ 0˚
10˚20˚ 30˚40˚50˚C
10W/30
15W/4020W/4020W/50
10W/40
5W/30
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8-59
3. Refill with the same type of brake fluid. Mixing
fluids may result in a harmful chemical reac-
tion and lead to poor brake performance. 
4. Be careful that water does not enter the mas-
ter cylinder when refilling. Water will signifi-
cantly lower the boiling point of the fluid and
may result in vapor lock. 
5. Brake fluid may deteriorate painted surfaces
or plastic parts. Always clean up spilled fluid
immediately. 
6. Have a Yamaha dealer check the cause if the
brake fluid level goes down. Recommended brake fluid: DOT 4
U4SH6A.book  Page 59  Thursday, May 30, 2002  1:25 PM 
     
        
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10-1
EBU00428
1-SPECIFICATIONS
Model YFM400FP/YFM400FW
Dimensions:
Overall length 1,956 mm
Overall width 1,155 mm
Overall height 1,144 mm
Seat height 845 mm
Wheelbase 1,210 mm
Minimum ground clearance 215 mm
Minimum turning radius 3,500 mm
Basic weight:
With oil and full fuel tank 286 kg
Engine:
Engine type Air-cooled 4-stroke, SOHC
Cylinder arrangement Forward-inclined single cylinder
Displacement 386 cm
3
Bore 
× stroke 83.0 ×
 71.5 mm
Compression ratio 8.6:1
Starting system Electric and recoil starter
Lubrication system Wet sump
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10-2
10
Noise and vibration level:
Noise level (77/311/EEC) 87.1 dB (A)
Vibration on seat (EN1032, ISO5008) Not exceed 0.5 m/s
2
Vibration on handlebar (EN1032, ISO5008) Not exceed 2.5 m/s
2
Engine oil/Transfer gear oil:
Type
Recommended engine oil classification: API Service SE, SF, SG type or higherModel YFM400FP/YFM400FW
-20˚-10˚0˚
10˚20˚30˚40˚50˚C
10W/30
15W/4020W/4020W/50
10W/40
5W/30
CAUTION:
In order to prevent clutch slippage (since the en-
gine oil also lubricates the clutch), do not mix any
chemical additives. Do not use oils with a diesel
specification of “CD” or oils of a higher quality
than specified. In addition, do not use oils labeled
“ENERGY CONSERVING II” or higher.
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10-3
Quantity:
Periodic oil change (engine oil): 2.4 L
Periodic oil change
(engine oil with oil filter replacement): 2.5 L
Periodic oil change 
(engine oil and transfer gear oil with 
oil filter replacement):2.8 L
Transfer gear case oil 0.3 L
Total amount 3.7 L
Final gear oil:
Type SAE 80 API “GL-4” Hypoid gear oil
Quantity
Periodic oil change 0.19 L
Total amount 0.25 L
Air filter: Wet type element
Differential gear oil:
Type SAE80 API “GL-4” Hypoid gear oil
Quantity:
Periodic oil change 0.47 L
Total amount 0.5 LModel YFM400FP/YFM400FW
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10-6
Suspension:
Front suspension Double wishbone
Rear suspension Swingarm (monocross)
Shock absorber:
Front shock absorber Coil spring / Oil damper
Rear shock absorber Coil spring / Oil damper
Wheel travel:
Front wheel travel 100 mm
Rear wheel travel 110 mm
Electrical:
Ignition system D.C. C.D.I.
Generator system A.C. magneto 
Battery type YTX 20L-BS
Battery voltage, capacity 12 V, 18 AH
Headlight type: Bulb type
Bulb voltage, wattage 
× quantity:
Headlight 12 V, 30 W / 30 W 
× 2
Tail / brake light 12 V, 5 W / 21 W × 1
Meter light 14 V, 3 W 
× 1
Indicator light:
Neutral 12 V, 1.7 W 
× 1
Reverse 12 V, 1.7 W × 1
Oil temperature 12 V, 1.7 W 
× 1 Model YFM400FP/YFM400FW
U4SH6A.book  Page 6  Thursday, May 30, 2002  1:25 PM