When we talk about motorbikes with carbureted engine there are two conditions that can be possible at any given point of time- the bike’s engine is either running Lean or it is running Rich. Since the engines with the fueling through Carburetors can be tuned manually we can always alter the condition by tuning the carburetor. But to tune any carburetor you must first know whether the engine is getting the lean mixture of air and fuel or it is getting the rich mixture.What is the Lean and Rich condition?
Well, as we all know that the job of the carburetor is to supply the mixture of air and fuel to the engine for the combustion. Now, this mixture should ideally be in a state of balance, where there is adequate air present with the oxygen to facilitate the process of combustion and there must also a sufficient amount of fuel in it. Based on the amount of air and fuel in the mixture it is decided whether the mixture is lean or it is rich.
Lean Condition:
The lean condition is a state where there is more air supply to the engine done through the carburetor as compared to the fuel. In easy terms there is less amount of fuel is supplied to the engine for combustion. The lean condition for an engine can be determined by many ways-
Troubleshooting Lean Condition:
1. One can easily spot a lean condition by the poor acceleration, the engine response gets flat and there is trouble in getting the engine accelerated.
2. The other commonly seen trait of lean mixture is, you won’t get the response when you suddenly whack the throttle wide open. Instead the bike picks up speed when the throttle is closed.
3. The engine gets hot pretty easily and the Knocking of the engine is experienced.
4. The engine runs very bad in winters or in cold weather, on the contrary it runs better in warm condition especially in summer season.
5. When the air filter gets removed the performance of the motorbike gets worse.
Ill Effects Of Lean Condition:
1. Poor Drivability.
2. Whole Engine can get destroyed in worst case scenario.
3. There could be hole in the piston.
4. The valves can be burnt.
5. The main bearings of the engine can also get spoiled.
1. One can easily spot a lean condition by the poor acceleration, the engine response gets flat and there is trouble in getting the engine accelerated.
2. The other commonly seen trait of lean mixture is, you won’t get the response when you suddenly whack the throttle wide open. Instead the bike picks up speed when the throttle is closed.
3. The engine gets hot pretty easily and the Knocking of the engine is experienced.
4. The engine runs very bad in winters or in cold weather, on the contrary it runs better in warm condition especially in summer season.
5. When the air filter gets removed the performance of the motorbike gets worse.
Ill Effects Of Lean Condition:
1. Poor Drivability.
2. Whole Engine can get destroyed in worst case scenario.
3. There could be hole in the piston.
4. The valves can be burnt.
5. The main bearings of the engine can also get spoiled.
Rich Condition:The rich condition is a state where the mixture is comprises of more or excessive fuel and less air. For the petrol-heads or the speed junkies the condition might look tempting but in fact the rich mixture has also drawbacks as the Lean mixture has. The rich condition can be determined by following ways-
Troubleshooting Rich Condition:
1. The engine runs on rich mixture does not have the smooth and crisp acceleration, in fact the acceleration tends to be flat and uneven. The engine looses the smoothness.
2. The engine idle becomes rough and pulsating; you need to blip the throttle to get it back to the idle.
3. It becomes difficult to maintain the acceleration and one has to keep the throttle open to get the engine accelerating.
4. Fowl sparkplug, the sparkplug often gets black and there is carbon deposit found on the sparkplug as well as on the exhaust pipe. Often you find black smoke coming out of the exhaust with the smell of unburned fuel.
5. Due to the excessive fuel used in the combustion the obvious Poor fuel economy can be observed.
6. The engine works better in winters or in cold conditions. The performance of the engine gets gradually declined while it warms up or the internal temperature of the engine rises.
7. When the air filter gets removed there is improvement seen in the performance of the engine running rich on mixture.
Ill Effects Of Rich Mixture:
1. Poor Fuel Economy
2. Waste of fuel as the extra fuel gets expelled out unburned.
3. Air pollution caused by the unburned fuel containing the hazardous gasses and residual carbon particles.
If you are facing any such issues, do consider these points and get your bike tuned accordingly to get the maximum out of your motorcycle and moreover to enjoy the pure motorcycling experience. Do let us know about your experiences in the comment section below.1. The engine runs on rich mixture does not have the smooth and crisp acceleration, in fact the acceleration tends to be flat and uneven. The engine looses the smoothness.
2. The engine idle becomes rough and pulsating; you need to blip the throttle to get it back to the idle.
3. It becomes difficult to maintain the acceleration and one has to keep the throttle open to get the engine accelerating.
4. Fowl sparkplug, the sparkplug often gets black and there is carbon deposit found on the sparkplug as well as on the exhaust pipe. Often you find black smoke coming out of the exhaust with the smell of unburned fuel.
5. Due to the excessive fuel used in the combustion the obvious Poor fuel economy can be observed.
6. The engine works better in winters or in cold conditions. The performance of the engine gets gradually declined while it warms up or the internal temperature of the engine rises.
7. When the air filter gets removed there is improvement seen in the performance of the engine running rich on mixture.
Ill Effects Of Rich Mixture:
1. Poor Fuel Economy
2. Waste of fuel as the extra fuel gets expelled out unburned.
3. Air pollution caused by the unburned fuel containing the hazardous gasses and residual carbon particles.
By: Farhan Kashif