Questions And Answers – Round 3 (Technical)

Till now I have got a few technical questions from various parts of India. All the questions and their answers are quite similar to each other. So I have made a full article by combining the answers which are suitable for everyone’s questions. Its sort of like a FAQ (Frequently asked Questions) list. Read on.

Almost all our motorcycles are equipped with chain drive systems. The initial pickup of lowe end torque can be increased quite easily by changing the rear sprocket. The sprocket should be switched from lower diameter to higher diameter. If the bike has 40 teeth on rear sprocket then switching to 42 teeth will give better low end performance. But this way the bike will lose its top end. Up-jetting the pilot jet is the next option. For initial or low end power the carburettor uses its slow running circuit to pump fuel into the engine until ¼ th of accelerator position is reached and after that it starts using the main jet circuit.

There are motorcycles that use large tyres with the combination of smaller cc engines. These motorcycles will need special attention because of it’s tolerance limit. For example Yamaha FZ series. The bike has bigger tyre than the rest but still has just a 150cc engine, The tyre would eat up a lot of initial power. To pump up a motorcycle like the FZ, the rider should choose the best combination of spares. But due to its engine limitations, the motorcycle can’t produce much more power than it was originally designed for. The initial pick up or low end torque are generally suitable for bikes that take part in Dirt Races, MotoCross or in any other types of professional stunts.

Some people always mention about the loss in power after switching to K&N. Well yes this happens. First of all when rider puts K&N or any performance oriented spares he should always check the condition of the engine, After a few thousand kilometres, the bike would be different in terms of performance due to the factors of wear and tear. The rider should always check the condition of clutch plates, friction plates and clutch springs, if they are not good, then its advisable to change them. Secondly, the timing chain or cam, is the most important spare in the bike. Some bikes are having push rod system and some have a timing chain system. The slackness or the play in cams can cause poor performance. For example, if the bike has a timing chain then rider should check the chain from a skilled mechanic for it’s slackness including its tensioner and pads. If the bike is has a push rod system for the valves. Then the rider should check the cams for backlash, Cam followers /lifters and Push rod settings. After these parts, the rider must check the carburettor settings including jet size. All induction type filters are basically free flow intakes, which shows quite impressive effect, but only if it is installed by skilled person. Yes!!!! K&N, PiperCross shows its real nature after installing. Many times I have noticed that people only put K&N to increase performance. Well it is absolutely wrong. By doing this, the bike or scooter will always lose the basic power. There are certain things which rider should work on after installing K&N/PiperCross or any performance filter. The first thing the rider or mechanic should do is to use a crank breather filter. The pipe which is connected to air box from crank case also needs a filter. In four stroke engines all the crank breather pipes are connected to an air box. Some vehicles which are equipped with Emission controlling kit are also connected to Air box for “O” molecule. When the mechanic installs the K&N filter directly on the carburettor. He would always forget about the crank breather, which he keeps open to atmosphere. Due to that the breather pipe starts breathing impure air directly from atmosphere. The reason behind giving breather pipe is for proper pure air. After working on K&N and crank breather then is the time for Jetting. Jetting means replacement of pilot and main jet as per the motorcycle or scooter requirement with higher size. Basically this is required because, a stock filter gives a 100% supply of air and when a K&N is installed, it changes that ratio to 120 to 130% that means the ratio of fuel has to be changed in the same manner in order to maintain the proper balance of air and fuel. So hence, jetting is necessary. For more detail please check out our: previous article regarding performance. This article clearly mentions about performance changes which are generally done.

For even more performance, NGK-IR plugs are best. People who are using them would give you the best review. I use these plugs for high performance purposes. These NGK-IR plugs are not only for fast racing or so, but they are also good for better mileage. In simple terms for the understanding of a layman is that these plugs have a better resistance power compared to conventional plugs, which gives a proper spark at all times. The fuel always needs proper spark to burn the Air fuel mixture in the combustion chamber. If there is a lack of current then the burning will be less and some of the fuel will not even be burnt and will be thrown out of the chamber. So zero performance loss and waste of fuel. For better “Voltage” there are some HT coils available which have a higher voltage than conventional HT coils.

Fuel Injection vehicles like the RTR-FI, P220-FI, R15, Glamour-FI are bit complicated to any freelance/regular mechanic. Its working principle may be the same but since its all electronic, mechanically altering the bike is quite complicated. FI systems do not have air-fuel screws like carburettor bikes. So changing the AF ratio is almost impossible by any rider. The ECU (Engine Control Unit) system works on a mathematical algorithm. The algorithm is written by engineers for getting optimal performance from the machine with the least fuel expense. The algorithm consists of a lot of parameters. A simple example of how the ECU works is the human body, An ECU on the same basic principle, Our human brain accepts and sends command through a pulse, the same way ECU accepts and sends the command to the proper sensor. All the sensors are given a specific task. So basically, the Air-Fuel mixture is controlled by various factors such as throttle position, intake air temperature, combustion chamber temperature, crank shaft position and several other sensors, the mixture is controlled by varying the pressure of the fuel injector, to increase or decrease the amount of fuel based on the sensor data. This is already programmed into the ECU and the factory designs it with the best possible setting. But one can modify it for better performance and that is called ECU/ECM remapping. Remapping alters fuel quantity that is injected, change in fuel pressure for proper fuel atomization. This is too complex for anyone other than professional programmers or re mappers. In India there are many people who claims that they can remap the ECU but the question is, are they qualified to do so over stock ECU/ECM mappers? Well no comments on that. But K&N and NGK will show effect on FI models but only if they are tuned properly from skilled persons or technicians. So it is best to buy a carburettor system than a FI system if you have plans to upgrade your bike, even though the FI system is superior to carburettor. Here I have mentioned the difference between any carburettor powered motorcycle and FI motorcycle.

First of all the FI system is depends on the ECU and the carburettor motorcycle works on C.B.Point / TCI / CDI. The best vehicle would be FI rather than carburetor machines at this point and stage. But all the systems have its own advantage or disadvantage. For example:-

Carburetor Version:

  1. Easy to maintain
  2. Easy for workmanship
  3. Easy to handle
  4. Anyone can service the bike.
  5. Anyone can screw up the settings.
  6. Spares are quite cheaper than FI.
  7. Mileage can be set manually but from skilled person
  8. Always a stone age technology in front of FI versions.
  9. Modification for performance can be done easily.
  10. No need of OBD (On Board Diagnostic Tool)/FIDT (Fuel Injection Diagnostic Tool) if they are running on CDI/TCI/C.B.Point, but if the bike has got ECU then it requires.
  11. Primitive technology in front of FI system.
  12. Not so much intelligent to find the error from its own network.

FI Version:

  1. Easy to handle
  2. Hard for servicing because Indian market has not matured enough to service it.
  3. Only Dealers or SC can service it, because they are trained for that.
  4. No one can tinker around settings so easily
  5. FI spares are always bit costlier than Carburettor versions.
  6. Its Space age technology in front of carburettor versions.
  7. Hard to modify for performance for any freelance or any mechanic.
  8. Mileage controlled by ECU, the manual setting is only for idling purpose.
  9. Need OBD/FIDT for system check
  10. Advance technology in front of carburettor engines.
  11. It is Intelligent enough to self diagnose.

These are some of the points which I know. The Carburettor system ruled the world for long period until FI came into the market, the charm of FI is always different. But the bad news is India is still not ready for FI motorcycles. The complicated system always takes some time to be known to all, which I believe. But I know soon that we will rock. The Indian automobile market has yet to become mature enough to handle any FI machines and their complications.

Someone asked me about plug numbers and suitability. Well NGK–Iridium can be fitted in almost all the vehicles. For example, Glamour carb /FI :- CPR6EAIX-9. The part number for NGK-IR is shown on their official website. Generally people get confused about K&N filters, spark plugs, performance spares and suitability of its shape for motorcycles or scooters. In India generally we all prefer Induction type RC-1060 or R1060 or R1100 for Indian vehicles. For SBK’s stock or induction type filters both are good.

The performance of any machine depends on many factors. Oil is the main and the most important factor which cannot be neglected at any cost. For any Indian motorcycle I would prefer oils as per company recommendation or higher than its API grade for example switching to API SM from API SL, but no change in grade number. For example:- 10W30, 20W40 or 20W50. But for performance it’s better to use a brand which can withstand heat, for example 15W50 API –SM, MA complaint from Motul this could be the best oil for performance oriented riders. The reason behind this grade is it starts getting thin after 50 degrees, so for long term usage the oil is useful. The lowest number in India is of no use because the grade 15, 0, 10 is good only for high altitude. Since most Indian machines are at sea level or low altitude. Secondly using of non MA/MA2 complaint oils causes lot of clutch slippage. Remember that all our machines are equipped with a wet clutch and not a dry system so it requires oil for better friction and cooling.

Performance oriented engines are not for optimal mileage. Stock engines which are not related to performance are mostly mileage oriented. So how I will get proper mileage from my vehicle? For example I am new or a would be owner of Karizma. So how I will take care and treat my machine for better mileage? Well answer is very simple. Taking care is not only washing the vehicle but also taking care of engine. All brand new engines have a break-in period. The engines which have all new spares take some time to get proper wear. Why wear and tear is needed? Well, for the parts to match each other for proper setting and synchronization, this kind of period is required. The stress which is caused by all the new moving parts may break each other due to rapid acceleration. The break-in term can also be assumed as though it’s an observation period. The way doctors keep their patients under observation, similarly any engine needs to be taken care of. In this period engine itself tells and shows the problems of spares. For example manufacturing issues, spare part quality issue and engine maturity. Once it covers the maturity level or the observation period or the break in period, engine is very much perfect for further service. During the break in period it is advisable to use the machine in proper manner. For example: – Speed limit, Acceleration limit, Load limit, Duration of running etc etc. The break in period makes engine smooth if the rider performs it as per the recommendation. The most important factor which can be calculated after or with break in period is mileage, A person who would abuse a machine during this period may not get the company stated average of mileage. Generally I have noticed that people do this because they simply can’t wait. I recommend 9000 km coverage with the speed limit of 40-50 Kmph for the machine, but it varies also. Because some of the motorcycles like MT01, R1, Hayabusa or the old but beautiful machine RD350, Royal Enfield’s new LB500 can’t ride at the speed of 40-50kmph in top gear. All these machines are powerful machine and loaded with high performance gear ratio. To use all the gears or mid range in these bikes is impossible, these bikes always need specific speeds for the given gears and its ratio. So for these powerful machines break in period is different. If we follow general break in then the vehicle will stall. Well, for all our Indian products and riders who are mileage concern should maintain their machines by proper handling. These are few tips which might help riders who are mileage concern.


  1. Regular servicing from SC or dealers.
  2. Using proper oil grade.
  3. Speed limit.
  4. Checking air pressure in tyres.
  5. If the vehicle is battery dependant then regular check for electrolyte quantity.
  6. Usage of proper OE spares.
  7. Avoid overload on engine and vehicle.
  8. Keep the vehicle clean and mud free or dust free or else it will block the important passages.
  9. Use proper fuel and bunks.
  10. Best fuel is regular unleaded regular fuel or Xtra premium.
  11. Battery terminal should be coated with Anti-Oxidation liquid/spray. If it is not available then go for petroleum jelly. Oxidation can make conductivity problem.
  12. Regular lubrication to main chain and given points.

– Chinmay Dangre