Yamaha YZ 2018 Series, Owner'S Service Manual

Page: 43 / 402

ENGINE SPECIFICATIONS
2-2
EASB29B054
ENGINE SPECIFICATIONS
Engine
Combustion cycle 4-stroke
Cooling system Liquid cooled
Valve train DOHC
Displacement 250 cm
3
Number of cylinders Single cylinder
Bore

stroke 77.0

53.6 mm (3.03

2.11 in)
Compression ratio 13.5 : 1
Starting system Electric starter
Fuel
Recommended fuel Premium unleaded gasoline (Gasohol [E10]
acceptable)
Fuel tank capacity 7.5 L (2.0 US gal, 1.7 Imp.gal)
Fuel reserve amount 2.1 L (0.55 US gal, 0.46 Imp.gal)
Engine oil
Recommended brand YAMALUBE
SAE viscosity grades 10W-40, 10W-50, 15W-40, 20W-40 or 20W-50
Recommended engine oil grade API service SG type or higher, JASO standard
MA
Lubrication system Wet sump
Engine oil quantity
Oil change 0.83 L (0.88 US qt, 0.73 Imp.qt)
With oil filter removal 0.85 L (0.90 US qt, 0.75 Imp.qt)
Quantity (disassembled) 1.10 L (1.16 US qt, 0.97 Imp.qt)
Oil filter
Oil filter type Paper
Oil pump
Inner-rotor-to-outer-rotor-tip clearance 0.000–0.150 mm (0.0000–0.0059 in)
Limit 0.23 mm (0.0091 in)
Outer-rotor-to-oil-pump-housing clearance 0.13–0.18 mm (0.0051–0.0071 in)
Limit 0.25 mm (0.0098 in)
Oil-pump-housing-to-inner-and-outer-rotor
clearance 0.06–0.11 mm (0.0024–0.0043 in)
Limit 0.18 mm (0.0071 in)
Cooling system
Coolant quantity
Radiator (including all routes) 1.00 L (1.06 US qt, 0.88 Imp.qt)
Radiator cap valve opening pressure 107.9–137.3 kPa (1.08–1.37 kgf/cm
2
,
15.6–19.9 psi)
Water pump
Water pump type Single suction centrifugal pump
Impeller shaft tilt limit 0.15 mm (0.006 in)
Spark plug(s)
Manufacturer/model NGK/LMAR8G
Spark plug gap 0.7–0.8 mm (0.028–0.031 in)
Cylinder head
Warpage limit 0.05 mm (0.0020 in)
Camshaft