compression ratio YAMAHA WR 250F 2016 Owners Manual

ENGINE SPECIFICATIONS
2-2
EAS2GB7062
ENGINE SPECIFICATIONS
Engine
Engine type Liquid cooled 4-stroke, DOHC
Displacement 250 cm
3
Cylinder arrangement Single cylinder
Bore  stroke 77.0  53.6 mm (3.0  2.1 in)
Compression ratio 13.5:1
Starting system Electric starter and kickstarter
Fuel
Recommended fuel Premium unleaded gasoline only
Fuel tank capacity 7.5 L (1.98 US gal, 1.65 Imp.gal)
Fuel reserve amount 1.6 L (0.42 US gal, 0.35 Imp.gal)
Engine oil
Lubrication system Wet sump
Recommended brand YAMALUBE
Type SAE 10W-40, SAE 10W-50, SAE 15W-40,
SAE 20W-40 or SAE 20W-50
Recommended engine oil grade API service SG type or higher, JASO standard
MA
Engine oil quantity
Quantity (disassembled) 1.10 L (1.16 US qt, 0.97 Imp.qt)
Without oil filter element replacement 0.83 L (0.88 US qt, 0.73 Imp.qt)
With oil filter element replacement 0.85 L (0.90 US qt, 0.75 Imp.qt)
Oil filter
Oil filter type Paper
Bypass valve opening pressure 40.0–80.0 kPa (0.40–0.80 kgf/cm
2,
5.8–11.6 psi)
Oil pump
Oil pump type Trochoid
Inner-rotor-to-outer-rotor-tip clearance Less than 0.150 mm (0.0059 in)
Limit 0.20 mm (0.0079 in)
Outer-rotor-to-oil-pump-housing clearance 0.13–0.18 mm (0.0051–0.0071 in)
Limit 0.24 mm (0.0094 in)
Oil-pump-housing-to-inner-and-outer-rotor
clearance 0.06–0.11 mm (0.0024–0.0043 in)
Limit 0.17 mm (0.0067 in)
Cooling system
Radiator (including all routes) 1.00 L (1.06 US qt, 0.88 Imp.qt)
Radiator capacity 0.56 L (0.60 US qt, 0.50 Imp.qt)
Radiator cap valve opening pressure 107.9–137.3 kPa (1.08–1.37 kg/cm
2,
15.6–19.9 psi)
Radiator core
Width 112.6 mm (4.43 in)
Height 235.0 mm (9.25 in)
Depth 28.0 mm (1.10 in)
Water pump
Water pump type Single suction centrifugal pump
Spark plug(s)
Manufacturer/model NGK/LMAR8G
Spark plug gap 0.7–0.8 mm (0.028–0.031 in)

ENGINE SPECIFICATIONS
2-5
Balancer
Balancer drive method Gear
Clutch
Clutch type Wet, multiple-disc
Clutch release method Inner push, cam push
Clutch lever free play 7.0–12.0 mm (0.28–0.47 in)
Friction plate thickness 2.90–3.10 mm (0.114–0.122 in)
Wear limit 2.85 mm (0.112 in)
Plate quantity 9 pcs
Clutch plate thickness 1.10–1.30 mm (0.043–0.051 in)
Plate quantity 8 pcs
Warpage limit 0.10 mm (0.004 in)
Clutch spring free length 47.80 mm (1.88 in)
Limit 46.80 mm (1.84 in)
Spring quantity 5 pcs
Push rod bending limit 0.10 mm (0.004 in)
Transmission
Transmission type Constant mesh 6-speed
Primary reduction system Spur gear
Primary reduction ratio 3.353 (57/17)
Final drive Chain
Secondary reduction ratio 3.846 (50/13)
Operation Left foot operation
Gear ratio
1st 2.385 (31/13)
2nd 1.813 (29/16)
3rd 1.444 (26/18)
4th 1.143 (24/21)
5th 0.957 (22/23)
6th 0.815 (22/27)
Main axle runout limit 0.08 mm (0.0032 in)
Drive axle runout limit 0.08 mm (0.0032 in)
Shifting mechanism
Shift mechanism type Shift drum and guide bar
Shift fork guide bar bending limit 0.050 mm (0.0020 in)
Shift fork thickness 4.85 mm (0.1909 in)
Decompression device
Device type Auto decomp
Air filter
Air filter element Wet element
Air filter oil grade Foam air-filter oil
Fuel pump
Pump type Electrical
Fuel injector
Model/quantity 30NA-FZ31/1
Resistance 12 

CHASSIS SPECIFICATIONS
2-8
Master cylinder inside diameter 9.52 mm (0.37 in)
Caliper cylinder inside diameter 22.65 mm  2 (0.89 in  2)
Specified brake fluid DOT 4
Rear brake
Type Single disc brake
Operation Right foot operation
Brake pedal position 5.0 mm (0.20 in)
Rear disc brake
Disc outside diameter  thickness 245  4.0 mm (9.6  0.16 in)
Brake disc thickness limit 3.5 mm (0.14 in)
Brake disc runout limit (as measured on wheel) 0.15 mm (0.0059 in)
Brake pad lining thickness (inner) 6.4 mm (0.25 in)
Limit 1.0 mm (0.04 in)
Brake pad lining thickness (outer) 6.4 mm (0.25 in)
Limit 1.0 mm (0.04 in)
Master cylinder inside diameter 11.0 mm (0.43 in)
Caliper cylinder inside diameter 25.40 mm  1 (1.00 in  1)
Specified brake fluid DOT 4
Steering
Steering bearing type Taper roller bearing
Center to lock angle (left) 43.0 °
Center to lock angle (right) 43.0 °
Front suspension
Type Telescopic fork
Spring/shock absorber type Coil spring/oil damper
Front fork travel 310.0 mm (12.20 in)
Fork spring free length 470.0 mm (18.50 in)
Limit 465.0 mm (18.31 in)
Fork spring installed length 470.0 mm (18.50 in)
Spring rate K1 4.40 N/mm (0.45 kgf/mm, 25.12 lbf/in)
Spring stroke K1 0.0–310.0 mm (0.00–12.20 in)
Inner tube outer diameter 48 mm (1.9 in)
Inner tube bending limit 0.2 mm (0.01 in)
Optional spring available Yes
Recommended oil Suspension oil S1
Quantity 540.0 cm
3 (18.26 US oz, 19.05 Imp.oz)
Rebound damping adjusting positions
Minimum 20 clicks out*
Standard 10 clicks out*
Maximum Fully turned in
* With the adjuster fully turned in
Compression damping adjusting positions
Minimum 20 clicks out*
Standard 11 clicks out*
Maximum Fully turned in
* With the adjuster fully turned in