Yamaha FZ750
Encyclopedia
The Yamaha FZ750 is a sport
motorcycle
produced by Yamaha Motor Corporation between 1985 and 1991. The FZ750 is notable as predecessor of the highly successful Yamaha FZR1000
.
s. The machine was noticeably narrower than many contemporaries. Yamaha achieved this by placing the alternator
behind the cylinders, instead of the more normal position: on the end of the crankshaft
.
The four 34 mm Mikuni constant-velocity downdraft carburettors
are mounted in a bank behind and above the cylinders and feed each cylinder through short intake manifolds
.
Four exhaust downpipes join a box below the engine where the gases are split to exit through two silencers.
The crankshaft is geared directly to the clutch
. No counter balancer shaft
is used. Starting is by electric starter only. Lubrication is wet sump using a trochoid
pump.
gearbox
; the gear shafts are only removable by splitting the crankcase halves.
The clutch is of the wet, multi-plate type and is hydraulically operated. Final drive is by O-ring chain
and sprocket
s. A safety feature of the FZ750 is that the engine ignition is cut if first gear is selected with the sidestand down; this is commonplace on modern motorcycles.
of the FZ750 is manufactured from mild steel
box-section and uses a perimeter layout. The fairing and upper rear section use separate cylindrical tubing sub-frames. The rear shock absorber
is placed vertically behind the engine and connects to an extruded
aluminium alloy
swinging arm via several forged aluminium rocker arms. The 16 inches (406.4 mm) front wheel is held between spring and oil damped forks
. Later models of the FZ750 used a 17 inches (431.8 mm) front wheel. Early FZ750s used twin ventilated disc brake
s for the front wheel with a single ventilated disc at the rear. Later versions used unventilated disks, with four piston calipers on the front.
electrical system. The alternator and starter motor are mounted behind the cylinders. Yamaha's self cancelling indicator unit is used and a variable-resistance gauging system
is used to monitor engine oil contents with associated warning lights. Nippondenso
Transistor Controlled Ignition (TCI)
is used in conjunction with two coils
.
Sport
A Sport is all forms of physical activity which, through casual or organised participation, aim to use, maintain or improve physical fitness and provide entertainment to participants. Sport may be competitive, where a winner or winners can be identified by objective means, and may require a degree...
motorcycle
Motorcycle
A motorcycle is a single-track, two-wheeled motor vehicle. Motorcycles vary considerably depending on the task for which they are designed, such as long distance travel, navigating congested urban traffic, cruising, sport and racing, or off-road conditions.Motorcycles are one of the most...
produced by Yamaha Motor Corporation between 1985 and 1991. The FZ750 is notable as predecessor of the highly successful Yamaha FZR1000
Yamaha FZR1000
The Yamaha FZR1000 is a motorcycle produced by Yamaha from 1987 to 1995. The 1989 version, crowned the "Bike of the Decade" by Cycle World, had 0-60 acceleration of 2.9 seconds, and a top speed of over 167 mph....
.
Development
Yamaha released the FZ750 in 1985. The bike was popular, and competed well against others in the "sport" class of motorcycleMotorcycle
A motorcycle is a single-track, two-wheeled motor vehicle. Motorcycles vary considerably depending on the task for which they are designed, such as long distance travel, navigating congested urban traffic, cruising, sport and racing, or off-road conditions.Motorcycles are one of the most...
s. The machine was noticeably narrower than many contemporaries. Yamaha achieved this by placing the alternator
Alternator
An alternator is an electromechanical device that converts mechanical energy to electrical energy in the form of alternating current.Most alternators use a rotating magnetic field but linear alternators are occasionally used...
behind the cylinders, instead of the more normal position: on the end of the crankshaft
Crankshaft
The crankshaft, sometimes casually abbreviated to crank, is the part of an engine which translates reciprocating linear piston motion into rotation...
.
Engine
The FZ750 uses an all-aluminium, liquid-cooled, tranverse-mounted, in-line, four-cylinder engine. The complex cylinder head is constructed in two halves, with dual chain-driven overhead camshafts operating 20 valves, 3 inlet and 2 exhaust per cylinder. Valve clearances are adjusted with under-lifter shims.The four 34 mm Mikuni constant-velocity downdraft carburettors
Carburetor
A carburetor , carburettor, or carburetter is a device that blends air and fuel for an internal combustion engine. It is sometimes shortened to carb in North America and the United Kingdom....
are mounted in a bank behind and above the cylinders and feed each cylinder through short intake manifolds
Inlet manifold
In automotive engineering, an inlet manifold or intake manifold is the part of an engine that supplies the fuel/air mixture to the cylinders...
.
Four exhaust downpipes join a box below the engine where the gases are split to exit through two silencers.
The crankshaft is geared directly to the clutch
Clutch
A clutch is a mechanical device which provides for the transmission of power from one component to another...
. No counter balancer shaft
Balance shaft
In piston engine engineering, a balance shaft is an eccentric weighted shaft which offsets vibrations in engine designs that are not inherently balanced...
is used. Starting is by electric starter only. Lubrication is wet sump using a trochoid
Gerotor
A gerotor is a positive displacement pumping unit. The name gerotor is derived from "Generated Rotor". A gerotor unit consists of an inner and outer rotor. The inner rotor has N teeth, and the outer rotor has N+1 teeth. The inner rotor is located off-center and both rotors rotate...
pump.
Transmission
The FZ750 uses a six-speed sequential close ratioClose-ratio transmission
A close-ratio transmission is a transmission in which there is little difference between the gear ratios of the gears. Consequently, note that the word close implies "near", not "shut." The gear ratio numbers are in a smaller numeric range, hence closer together.In the context of close-ratio...
gearbox
Manual transmission
A manual transmission, also known as a manual gearbox or standard transmission is a type of transmission used in motor vehicle applications...
; the gear shafts are only removable by splitting the crankcase halves.
The clutch is of the wet, multi-plate type and is hydraulically operated. Final drive is by O-ring chain
O-ring chain
The o-ring chain is a specialized type of roller chain used in the transmission of mechanical power from one sprocket to another.- Construction :...
and sprocket
Sprocket
A sprocket or sprocket-wheel is a profiled wheel with teeth, cogs, or even sprockets that mesh with a chain, track or other perforated or indented material. The name 'sprocket' applies generally to any wheel upon which are radial projections that engage a chain passing over it...
s. A safety feature of the FZ750 is that the engine ignition is cut if first gear is selected with the sidestand down; this is commonplace on modern motorcycles.
Chassis
The frameMotorcycle frame
A motorcycle frame includes the head tube that holds the front fork and allows it to pivot. Some motorcycles include the engine as a load-bearing, stressed member. The rear suspension is an integral component in the design. Traditionally frames have been steel, but titanium, aluminium, magnesium,...
of the FZ750 is manufactured from mild steel
Steel
Steel is an alloy that consists mostly of iron and has a carbon content between 0.2% and 2.1% by weight, depending on the grade. Carbon is the most common alloying material for iron, but various other alloying elements are used, such as manganese, chromium, vanadium, and tungsten...
box-section and uses a perimeter layout. The fairing and upper rear section use separate cylindrical tubing sub-frames. The rear shock absorber
Shock absorber
A shock absorber is a mechanical device designed to smooth out or damp shock impulse, and dissipate kinetic energy. It is a type of dashpot.-Nomenclature:...
is placed vertically behind the engine and connects to an extruded
Extrusion
Extrusion is a process used to create objects of a fixed cross-sectional profile. A material is pushed or drawn through a die of the desired cross-section...
aluminium alloy
Aluminium alloy
Aluminium alloys are alloys in which aluminium is the predominant metal. The typical alloying elements are copper, magnesium, manganese, silicon and zinc. There are two principal classifications, namely casting alloys and wrought alloys, both of which are further subdivided into the categories...
swinging arm via several forged aluminium rocker arms. The 16 inches (406.4 mm) front wheel is held between spring and oil damped forks
Motorcycle fork
A motorcycle fork connects a motorcycle's front wheel and axle to its frame, typically via a pair of triple clamps. It typically incorporates the front suspension and front brake, and allows the bike to be steered via handlebars attached to the top clamp....
. Later models of the FZ750 used a 17 inches (431.8 mm) front wheel. Early FZ750s used twin ventilated disc brake
Disc brake
The disc brake or disk brake is a device for slowing or stopping the rotation of a wheel while it is in motion.A brake disc is usually made of cast iron, but may in some cases be made of composites such as reinforced carbon–carbon or ceramic matrix composites. This is connected to the wheel and/or...
s for the front wheel with a single ventilated disc at the rear. Later versions used unventilated disks, with four piston calipers on the front.
Electrical system
The FZ750 features a standard 12 voltVolt
The volt is the SI derived unit for electric potential, electric potential difference, and electromotive force. The volt is named in honor of the Italian physicist Alessandro Volta , who invented the voltaic pile, possibly the first chemical battery.- Definition :A single volt is defined as the...
electrical system. The alternator and starter motor are mounted behind the cylinders. Yamaha's self cancelling indicator unit is used and a variable-resistance gauging system
Level sensor
Level sensors detect the level of substances that flow, including liquids, slurries, granular materials, and powders. Fluids and fluidized solids flow to become essentially level in their containers because of gravity whereas most bulk solids pile at an angle of repose to a peak...
is used to monitor engine oil contents with associated warning lights. Nippondenso
DENSO
is a global automotive components manufacturer headquartered in the city of Kariya, Aichi Prefecture, Japan. Established December 16, 1949 as , in 1996 the company became DENSO Corporation worldwide...
Transistor Controlled Ignition (TCI)
Capacitor discharge ignition
Capacitor discharge ignition or thyristor ignition is a type of automotive electronic ignition system which is widely used in outboard motors, motorcycles, lawn mowers, chainsaws, small engines, turbine-powered aircraft, and some cars...
is used in conjunction with two coils
Ignition coil
An ignition coil is an induction coil in an automobile's ignition system which transforms the battery's 12 volts to the thousands of volts needed to create an electric spark in the spark plugs to ignite the fuel...
.
Specifications (FZ750)
Data from:| FZ750 | ||
|---|---|---|
| Engine | 749 cc, 4-stroke, four-cylinder, liquid-cooled, in-line | |
| Bore Stroke | 68 x 51.6 mm | |
| Compression Ratio | 11.2:1 | |
| Fuel System | Mikuni BS34 34 mm carburettor x 4 | |
| Lubrication | Wet sump | |
| Ignition | TCI (Digital) | |
| Transmission | 6-speed, constant mesh | |
| Final Drive | Chain | |
| Overall Length | 2225 mm (87.6 in) | |
| Overall Width | 755 mm (29.7 in) | |
| Overall Height | 1165 mm (45.9 in) | |
| Seat Height | 790 mm (31.1 in) | |
| Ground Clearance | 155 mm (6.1 in) | |
| Wheelbase | 1490 mm (58.7 in) | |
| Dry Weight | 210 kilograms (463 lb) | |
| Suspension Front | Telescopic, coil spring. | |
| Suspension Rear | Link-type, gas/oil damped. | |
| Brakes Front | Dual hydraulic disc | |
| Brakes Rear | Single hydraulic disc | |
| Tyres Front | 120/80-HR16 | |
| Tyres Rear | 130/80-HR18 | |
| Fuel Tank Capacity | 21 L | |
| Colours | ||