A two wheeler is generally operated by a 2- stroke spark ignition internal combustion engine
which supplies power to the wheels. The efficiency of which depends mainly on the compression
ratio and speed of rotation.
The Development of two wheeled scooters, motor cycles, mopeds and 3-wheelers equipped
with-2 stroke cycle engine is the outcome of research for a low cost mode of travel. These vehicles
are easy to drive and have good maneoeuvrability.
There has been a steady growth in the population of the/ three wheelers in our country. In March,
1996 the total population of two/tree-wheelers in the country was estimated at 24 million vehicles.
The Indian two-wheelers are mostly fitted with conventional 2- stroke engines. However, a few
manufacturers have introduced 4- stroke engine, the 4-strock engine has higher fuel efficiency, better
volumetric efficiency, complete fuel combustion and minimum air pollution. The engine is provided
with a separate oil tank to supply lubrication oil through the oil pump. At low speed and low load
extra oil is not supplied to the engine. This minimizes oil consumption and maximizes the interval
between de-carbonisation and thereby minimizes air pollution
Circulate free in public interest by P.C.R.A.
SUPERIOOR 2T OILS
The oil companies have developed superior 2T oils specially for use in 2 stroke engines as
lubricating oil to be mixed with fuel in the recommended dosage at the time of filling.
The benefits of using superior 2T oils in the right proportion are: –
a) Excellent lubrication of engines at all operating temperatures and under the most adverse conditions.
b) Reduced spark plug fouling which also reduces maintenance cost.
c) Deposits formation in combustion chamber, exhaust port and the muffler is reduced,
thereby extending the periods between decarbonisation and leading to reduced power
d) Reduced wear of piston rings, cylinder, cylinder liners and associated components
thereby lengthening of the life of the engine.
e) Optimum performance of the engine.
GOOD DRIVING SKILLS AND MAINTENACNE PRACTICES
1. Drive steadily and at the optimum speed :- Drive at an optimum speed of 30-40 kmph.
You will be surprised to find that your travel time does not increase significantly. Sudden
starts and ‘stop-and-ago’ driving waste fuel. Research shows that fat and rash driving can
increase fuel consumption substantially.
2. Use brakes sparingly :– A good driver anticipates stops. When you slam on the brakes, you
waste a lot of useful energy. Anticipate corner- you will be able to negotiate them without
3. Let go of your clutch: – Unnecessary use of the clutch leads to loss of power.
4. Clean air filter regularly:- Dust leads to rapid wear of engine components and increases
fuel combustion. Choked exhaust ports & Silencer make your engine struggle to breathe,
causing poor combustion.
5. Watch your tyre pressure: – Under inflated tyres increase rolling resistance and petrol
consumption. Tests show that under inflation of tyres by 25 % causes a 5 % increase in fuel
consumption and a 25% decrease in tyre life.
6. Stop fuel leaks :– Check your fuel tank, carburetor, and fuel lines daily for sings of leaking
fuel. Loss of one drop of fuel per second amounts to nearly 2000 litres per year.
7. Stop the engine if you stop for more than 2 minuets :- Idling can cost money- and fuel.
Stop your engine at long waits, for example, at railway crossings.
8. Keep your engine in good condition :– Tests on a large number of vehicles show that you
can save over 6% fuel by regular tuning. If your engine emits smoke of has poor pulling
power, have it checked immediately at a reputed garage.
9. Use superior 2T oils for lubrication :– Mix superior 2T oil conforming to international
API/TC specifications in recommended dosage to derive various benefits.
ECONOMICAL GEAR SHIFTING
Different gears are provide to use the power of the engine to suit the work it has to do. In a
low gear, the engine revolution is faster, and so it consumes more fuel than it normally would
at the same road speed in a higher gear. For maximum fuel economy, gear changes must be
made at the right moment, that is when the speed you have reached in a low gear can be
maintained without increase acceleration in the next higher gear, or when you change down
without causing noisy, racing surge in the engine speed. Please follow the speed limits in the
engine speed. Please follow the speed limits for economical gear shifting as recommended by
FUEL EFFICIENCY NORMS
Developed by Ministry of Industry Government of Indian
on the basis of trials carried out at Automotive Research
Association of India ( ARA) and Vehicle Research &
Development establishment ( VRDE).
Engine Capacity Kms/ litre of gasoline (min)
Less than 35 C.C. 95
35 C.C. to 75 C.C. 87
( Variable transmission)
35 C.C. to 75 C.C. 83
( Fixed transmission)
75 C.C. to 200 C.C. 60
Greater than 200 cc 55
PROBABLE CASUES OF HIGHT FUEL CONSUMPTION AND REMEDIES
1. Spark plug defects – Adjust gap and clean the plug point, Replace if
2. Fuel system Carburettor clogged/dirty – Check for, fuel leaks & rectify
– Clean fuel, tank fuel tube, jet & carburetor body.
3. Air cleaner choked/dirty – Remove and clean it with air petrol and blow dry
4. Choke value sticking in closed position – Lubricate the choke control lever and keep it in
5. Hard to start due to over flow of the engine – Check points 1 to 4 given above while parking keep
fuel value in closed position and park at a paper
6. Silencer outlet pipe choked – Clean .
7. Vehicle drag on the road – Check tyre pressure and fill air, if necessary.
8. Poor braking – Adjust brake pedal lever free play.
9. Poor pick-up – Check spark plug for correct fitment in the cylinder
head. Check points 1 to 8 given above.
10. Lack of power – Contact authorized service, station.
RECOMMENDED MAINTENANCE SCHEDULE FOR OPTIMU FUEL
1. By owner Clean Adjust Lubricate Replace Frequency
i) Spark Plug ™ ™ ™ Monthly 8,000 kms
ii) Air filter ™ – – – Monthly
iii) Gear Oil – – – ™ As recommended by mfrs.
iv) Petrol strainer ™ – – ™ Refill
v) Fuel lines ™ ™ – – Monthly
vi) Carburettor ™ ™ – – Monthly
vii) Tyre pressure – ™ – – Refill
II- By authorized mechanic
i) Carburettor ™ ™ – – 4,000 Kms.
ii) Air filter ™ – – – 5,000 Kms.
iii) Throttle Operation – ™ ™ – 2,000 Kms.
iv) Front & rear Brake controls – ™ ™ – 4,000 Kms.
v) Clutch & gear levers – ™ ™ – -dovi)
Flywheel magneto ™ ™ – – -dovii)
De- carbonizing cylinder,
piston head & silencer
™ – – -doviii)
Other fitments – ™ ™ -do