compression ratio YAMAHA YZF-R7 1999 Owners Manual

1 - 25
SPECIAL TOOLS
Compression
gauge
90890-03081
Adapter
90890-04136Compression gauge
Adapter
These tools are used to measure engine
compression.
90890-03112Pocket tester
This tool is used to check the electrical
system.
Pressure
gauge
90890-03153
Adapter
90890-03151Pressure gauge
Adapter
These tools are used to measure the fuel
pressure.
90890-03149Test coupler adapter
This tool is used to check the electrical
control system.
90890-03171Co, diagnosis switch box
This tool is used to check the electrical
control system.
Valve spring com-
pressor
90890-04019
Attachment
90890-04108
90890-04114
Valve spring compressor
Attachment
These tools are used to remove or install
the valve assemblies.
Middle driven shaft
bearing driver
90890-04058
Mechanical seal
installer
90890-04078
Middle driven shaft bearing driver
Mechanical seal installer
These tools are used to install the water
pump seal.
90890-04086Clutch holding tool
This tool is used to hold the clutch boss
when removing or installing the clutch
boss nut.
90890-04111Valve guide remover
This tool is used to remove or install the
valve guides.
Tool No. Tool name/Function Illustration
MODEUP
YES/ON
DOWN
NO/OFF

ENGINE SPECIFICATIONS
SPEC

2 - 2
ENGINE SPECIFICATIONS
Item Standard Limit
Engine
Engine type Liquid-cooled, 4-stroke, DOHC ----
Displacement 749 cm
3

----
Cylinder arrangement Forward-inclined parallel 4-cylinder ----
Bore
´
stroke 72
´
46 mm (2.83
´
1.81 in) ----
Compression ratio 11.4:1 ----
Engine idling speed 1,000 ~ 1,200 r/min ----
Vacuum pressure at engine idling
speed15.8 ~ 18.4 kPa
(120 ~ 140 mm Hg, 4.72 ~ 5.51 in Hg)----
Standard compression pressure
(at sea level) 157 kPa
(1.57 kgf/cm
2

, 22.3 psi) at 500 r/min----
Fuel
Recommended fuel Premium unleaded gasoline ----
Fuel tank capacity
Total (including reserve) 23 L (20.2 Imp qt, 24.3 US qt) ----
Reserve only 4.8 L (4.22 Imp qt, 5.07 US qt) ----
Engine oil
Lubrication system Wet sump ----
Recommended oil
Yamalube 4 (20W40) or SAE 20W40 type
SE motor oil (40˚F/5˚C or above)
(Non-Friction modified)
Yamalube 4 (10W40) or SAE 10W40 type
SE motor oil (60˚F/15˚C or below)
(Non-Friction modified)----
Quantity
Total amount 3.6 L (3.2 Imp qt, 3.8 US qt) ----
Without oil filter cartridge
replacement2.6 L (2.3 Imp qt, 2.7 US qt) ----
With oil filter cartridge replace-
ment2.8 L (2.5 Imp qt, 3.0 US qt) ----
Oil pressure (hot) 40 kPa (0.4 kgf/cm
2

, 5.69 psi) at
1,100 r/min ----
Relief valve opening pressure 480 ~ 560 kPa
(4.8 ~ 5.6 kgf/cm
2

, 68.3 ~ 79.7 psi)----
2

ENGINE SPECIFICATIONS
SPEC

2 - 7
Outer springs
Free length
Intake 36.42 mm (1.43 in) 34.60 mm
(1.36 in)
Exhaust 33.91 mm (1.34 in) 32.21 mm
(1.27 in)
Installed length (valve closed)
Intake 32.03 mm (1.26 in) ----
Exhaust 30.25 mm (1.19 in) ----
Compressed spring force
(installed)
Intake 230 ~ 266 N
(23.45 ~ 27.12 kgf, 51.7 ~ 59.8 lb)----
Exhaust 286 ~ 329 N
(29.16 ~ 33.55 kgf, 62.3 ~ 74.0 lb)----
Spring tilt
Intake ----2.5˚ /1.6 mm
(2.5˚/0.063 in)
Exhaust ----2.5˚ /1.5 mm
(2.5˚/0.059 in)
Winding direction (top view)
Intake Clockwise ----
Exhaust Clockwise ----
Cylinders
Cylinder arrangement Forward-inclined, parallel 4-cylinder ----
Bore

´

stroke 72
´
46 mm (2.83
´
1.81 in) ----
Compression ratio 11.4:1 ----
Bore 72.000 ~ 72.008 mm
(2.8346 ~ 2.8350 in)----
Maximum taper ---- 0.05 mm
(0.0016 in)
Maximum out of round ---- 0.05 mm
(0.0016 in) Item Standard Limit