Dealer Development Center, Pune
36
Pulsar DTS-i 150/180 Training Notes
Dos & Don’ts
• Don't reuse 'O' rings, gaskets, Oil seals, Circlip locks as they use
their strength & properties, once they are opened.
• Don't adjust spark plug electrode gap by hacksaw blade or with
judgement of eye otherwise it will affect the engine performance.
• Don't adjust valve tappet clearance by hacksaw blade or with
judgement of eye otherwise it will affect the engine performance.
• Don't set valve tappet clearance in engine hot condition.
• While removing rotor, don't rest the rotor holder & special tool
against gear change lever.
• Don’t over tighten cylinder head cover bolts.
• Don’t fit 2nd piston ring ‘UP’ side ‘Down’. This could lead to
smokey exhaust & higher engine oil consumption.
• Don't wash engine bearings with water.
• Don't blow compressed air on engine bearing otherwise they will
get permanently spoiled.
Don’ts
7
Dealer Development Center, Pune
37
Pulsar DTS-i 150/180 Training Notes
CAT Converter
Function
The air fuel mixture which is burnt inside the combustion chamber does not burn completely and give rise
to harmful gases like carbon monoxide (CO); Hydrocarbon (HC) and Nitrogen oxide (NO ). The cat
x
converter converts these harmful gases into harm less gases. The catalyst is a material in the catalytic
converter that causes the chemical change without being a part of chemical reaction. In effect the catalyst
encourages chemicals to react with each other.
Working
0
When the engine starts the temperature at the exhaust port is around 500 C.
0
The cat converter operates at 250 - 300 C. As the exhaust gases pass over
the larger surface area coated with catalyst the chemical reaction takes
place. The harmful gases are converted into harmless gases because of the
chemical reaction.
CO + HC + No changes to Co + H O + N
x
2
2
Thus it converts hazardous gases into harmless gases.
Construction
A catalytic converter is fitted inside the silencer body after the ExhausTEC
port and consist of 4 main parts.
1.
The substrate or the support which is of honeycomb ceramic type or
metallic type.
2.
The wash coat or intermediate layer such as alumina which provides a
suitable surface for adhesion of the noble metals on to substrate surface
and facilitate high thermal stability during the chemical reaction.
3.
Catalyst material (noble material) like Palladium, Platinum, Rhodium in
different proportions are (which is thin layer) deposited on the wash
coat.
4.
Housing or canning is the outer cover of the unit which can be
interfaced with the vehicle exhaust system.
Silencer Body
Catalytic Converter
Container
Substrate
Catalyst Material
(Coating of Noble Metals)
Gases Present
- Converted into
•
Carbon monoxide CO
- Carbon Dioxide CO
2
•
Hydrocarbons HC
- Carbon DioxideCO and Water Vapour H O
2
2
•
Nitrogen Oxide No
- Nitrogen N
x
2
No
x.
CO
2
A catalytic converter may have two different catalysts. One catalyst treats the HC and CO The other treats
The catalyst for HC and CO encourages the HC to unite with Oxygen to become H O (Water) and
2
(carbon dioxide). It also encourages the CO to unite with Oxygen to become Co or Carbon Dioxide.
2
This type of converter is an oxidizing converter, because it oxidizes the HC and CO (To oxidize means to
combine with oxygen). The metals like Platinum and Palladium are used as oxidizing catalysts.
The catalyst for the No works differently. It splits the oxygen from the Nitrogen. The No becomes
x
x
harmless Nitrogen and Oxygen. This type of converter is a reducing converter. The metal Rhodium
reduces the NO to Nitrogen and Oxygen.
x
The silencer with the catalytic converter has been matched and designed to give optimum engine
performance and very good reduction in emission level to meet the emission norms.
Don’ts
1.
Do not pour 2T oil / Engine oil into silencer.
2.
Do not turn off the ignition key when the vehicle is in gear / running condition. Bring the engine into
neutral & then put off the ignition.
3.
In case of carburettor flooding / overflow immediately rectify the defect too rich mixture flowing down
the cat converter might lower down its efficiency.
