Four stroke, single cylinder, SOHC,
2 valves per cylinder.
Capacity
499 cc / 30.4 cu-in
Bore x Stroke
87 х 84 mm
Cooling System
Air cooled
Compression Ratio
9.0:1
Oil Capacity
2.4 Litres
Induction
34mm Mikuni VM34SS carburetor
Ignition
CDI
Starting
Kick
Max Power
31.5 hp / 23.5 kW @ 6500 rpm
Max Torque
36.3 Nm / 26.8 lb-ft @ 5500 rpm
Transmission
5 Speed
Final Drive
Chain
Frame
Half-duplex cradle
Front Suspension
35mm telescopic forks
Front Wheel Travel
150 mm / 5.9 in
Rear Suspension
Dual shock, 5-way adjustable spring
preload.
Rear Wheel Travel
105 mm / 4.1 in
Front Brakes
Single 200mm disc
Rear Brakes
150mm drum
Front Tyre
3.50 S19
Rear Tyre
4.00 S18
Rake
27.5°
Trail
117 mm / 4.6 in
Dimensions
Width 845 mm / 33.3 in
Height 1155 mm / 45.5 in
Wheelbase
1405 mm / 55.3 in
Seat Height
810 mm / 32 in
Dry Weight
158 kg / 348 lbs
Wet Weight
173 kg / 381.4 lbs
Fuel Capacity
12 Litres / 3.1 US gal
Consumption Average
63 mpg
Standing
¼ Mile
15.3 sec
Top Speed
95 mph / 152.8 km/h
The SR500, in
true Japanese fashion, is a well engineered bike and in most places the toil
of owning such a machine has been developed out: like leaks, dubious
electrics and general lack of reliability. The machine is powered by an
oversquare engine of 499CC with valve actuation by a single overhead
camshaft. Essentially the same alloy unit as the XT off roader, the SR
differs in valves size and port shape so is a little more potent. A maximum
power figure of 33bhp at 65oorpm is not a lot for a 500, but peak torque is
just over 281b ft at 55oorpm, and indeed the torque curve is remarkably flat
from 2ooorpm to that figure. A five-speed gearbox is used and the bike will
reach a top speed of just on 90mph in the highest of them. Fuel consumption
is a bonus feature of such a bike and the SR500 should have no difficulty in
producing an overall figure of well over 5ompg.
Rather than try to get a starter
to turn over a 500CC cylinder with a 9:1 compression ratio, Yamaha decided
to leave firing to a hefty rider, although they do make it as easy as
possible. A compression release lever is fitted and the engine is turned
carefully so that the piston is at the top of its stroke. A little window on
the camshaft cover indicates when this point has been reached. The bike
should then fire at the first kick. A vacuum automatic advance and retard
system (like that of the XS1100) also helps. Also dispensing with an
electric starter helps save weight as again a plus point of a single is that
it is quite light. Dry weight of the machine is 3481b so a single disc brake
at the front and drum rear ably stop it. Handling is good, too, and the
narrow bike instils a lot of confidence in the rider to make full use of it.
The SR500 Yamaha may not suit
everyone, but it does take the tears out of 'vintage biking'.
The indicator switch can be
simply pressed inwards to override the unit.
Any corrections or more information on these motorcycles will be kindly appreciated.