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Yamaha XJ750-D Fuel Injection (Model 22N)1984. | Yamaha XJ750-P Police Special (Model 24L) 1985. | XJ750-D2 Fuel Injection (Model 38X) 1985
Yamaha XJ750-D Fuel Injection (Model 22N)1984.
This bike is a little more unusual. It was made for the Japanese home market only and is one of the earliest examples of fuel injection used on a motor cycle.
It is based on the same body style as used on the Yamaha XJ-650-Turbo.
It boasts a fully digital dash board with a ten function on-board fuel economy computer that includes a clock, up-count trip meter, set-able down-count trip meter, fuel remaining in tank (ltrs), fuel economy (as you ride, updated every 30 seconds) range on remaining fuel, time spent on trip, average speed, fuel consumption, and average economy.
There is also a seven function monitor that activates a large warning light on the dash and displays an LCD icon to warn if the side stand is down or brake, oil, battery or fuel levels are low. It also warns of lamp failure in the head or tail lights and provides a fuel gauge.
Originally these bikes were all silver with either red or gray decals depending on year of manufacture.
When I purchased my injection the previous owner had repainted it blue with red pearl, I liked the change so kept it. I am not really keen on the original silver paint work.
The fuel injection is the electronic multi point type with the injectors housed in four simple throttle body's with the usual cable actuation via a twist grip on the right handle bar.
Intake air flow is monitored by an airflow sensor in the air box and a boost sensor piped to one inlet manifold.
The fuel pump is an electric 'disk and roller' type pump. Normally these bikes use a Hitachi pump but mine had failed and the closest equivalent I could find was a Airtex EP6910 EFI pump. It seems to perform well.
The engine / gearbox and final drive are the same as used on the other early 1980's XJ 750's.
Specifications;
Model
|
YAMAHA XJ750-D
|
|
Frame No.
|
5G8-021058
|
|
Engine Model
|
5G8
|
|
Manufactured since
|
Aug.1982
|
|
Dimensions
|
Overall Length
|
2170 mm
|
Overall width
|
730 mm
|
|
Overall height
|
1365 mm
|
|
Seat height
|
785 mm
|
|
Wheelbase
|
1440 mm
|
|
Minimum road clearance
|
140 mm
|
|
Weight
|
Dry
|
231 kg
|
With oil and full fuel tank
|
254 kg
|
|
Seating capacity
|
2
|
|
Performance
|
Climbing capacity
|
30¡
|
Minimum turning radius
|
2700 mm
|
|
Stop length
|
15 m (50km/h)
|
|
Engine
|
Type
|
4 stroke, gasoline, air-cooled, DOHC
|
Cylinder
|
4-cylinder, inline type
|
|
Displacement
|
748cm^3 (45.6 cu.in)
|
|
Bore x stroke
|
65.0 mm x 56.4 mm
|
|
Compression ratio
|
9.2
|
|
Compression pressure
|
9.0kg/cm^2 - 300rpm
|
|
Horsepower
|
70PS/9000r.p.m.
|
|
Torque
|
6.2kg-m/7000r.p.m.
|
|
Air cleaner
|
Dry type
|
|
Clutch type
|
Wet, multiple-disk
|
|
Gear box type
|
Constant mesh, 5-speed forward
|
|
Starting System
|
Electric starter
|
|
Ignition System
|
Battery ignition (Full transistor ignition)
|
|
Chassis
|
Frame type
|
Double cradle
|
Steering: Caster
|
28¡
|
|
Trail
|
115 mm
|
|
Angle
|
Each 35¡
|
|
Fuel tank capacity
|
19 L
|
|
Braking system: Front
|
Double disk brake/Right hand operation
|
|
Rear
|
Drum brake/Left foot operation
|
|
Suspension: Front
|
Telescopic fork with anti-dive
|
|
Rear
|
Swing arm
|
|
Shock absorber: Front
|
Coil/air spring, oil damper
|
|
Rear
|
Air/gas/coil spring, oil damper
|
|
Tire size: Front
|
3.25H19-4PR (100/90R19 57H) Tubeless tire
|
|
Rear
|
120/90-18 65 Tubeless tire
|
|
Gear
|
Primary reduction ratio
|
97/58 (1.672)
|
Ratio
|
First 35/16 2.187
Second 30/20 1.500
Third 30/26 1.153
Fourth 28/30 0.933
Fifth 26/32 0.812
|
|
Secondary reduction ratio
|
48/37 x 19/18 x 32/11
(1.297 x 1.055 x 2.909)
|
|
Engine oil quantity
|
Periodic oil change
|
2200 cm^3
|
With oil filter replacement
|
2500 cm^3
|
|
Total amount
|
3200 cm^3
|
|
Fuel injection system
|
Type
|
Injector
|
Nozzle
|
Ball type, 1 for each cylinder
|
|
Injector diameter
|
0.55 mm
|
|
Idling
|
1050 r.p.m.
|
|
Idling boost pressure
|
>185 mmHg
|
|
Tire air pressure
|
1 passenger
|
Front 1.75kg/cm^2
Rear 2.00kg/cm^2
|
2 passengers
|
Front 2.00kg/cm^2
Rear 2.25kg/cm^2
|
|
High speed
|
Front 2.00kg/cm^2
Rear 2.25kg/cm^2
|
|
Battery
|
Type
|
SYB-14L-A2
|
Capacity
|
12V, 14Ah
|
|
Regular charge
|
1.4 A x 10 hour
|
|
Generator
|
Type
|
LD119-19
|
Manufacturer
|
Hitachi, Ltd.
|
|
Voltage
|
12 V
|
|
Output
|
14V-26A
|
|
Regulator
|
Type
|
S8534
|
Manufacturer
|
Nippon Denso, Ltd.
|
|
Regulation voltage
|
14.5 V
|
|
Starter
|
Type
|
ADB4D2
|
Manufacturer
|
Nippon Denso, Ltd.
|
|
Voltage
|
12 V
|
|
Output
|
0.6 KW
|
|
Ignition coil
|
Type
|
CM12-09
|
Manufacturer
|
Hitachi, Ltd.
|
|
Spark plug
|
NGK BPR7ES,BP7ES
Nippon Denso W22PR,W22EP
|
|
Electrical
|
Headlight
|
12V,60/55W (Halogen Bulb, Quartz)
|
Tail/brake light
|
12V,27/8W x 2
|
|
Marker light
|
12V,3.4W
|
|
License light
|
12V,3.4W x 2
|
|
Flasher light
|
12V,27W x 4
|
|
Meter light (Tachometer)
|
12V,3.4W
|
|
Meter light (Speedometer)
|
12V,2W x 5
|
|
Pilot lights:NEUTRAL
|
12V,3.4W
|
|
HIGH BEAM
|
12V,3.4W
|
|
SPEED ALARM
|
12V,3.4W
|
|
TURN
|
12V,3.4W x 2
|
|
ALARM INDICATOR
|
12V,3.4W
|
|