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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