Yamaha YZ 2019 Series, Owner'S Service Manual

Page: 43 / 398

ENGINE SPECIFICATIONS
2-2
EAM20128
ENGINE SPECIFICATIONS
Engine
Combustion cycle 4-stroke
Cooling system Liquid cooled
Valve train DOHC
Displacement 250 cm³
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] ac-
ceptable)
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/cm², 15.6–19.9
psi)
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
Camshaft cap inside diameter 22.000–22.021 mm (0.8661–0.8670 in)
Camshaft journal diameter 21.959–21.972 mm (0.8645–0.8650 in)