Air Filters - Universal Thread

[aarunn]

any one using Green cotton filters?

[abhijeetbuzz]

Intsalled K&n on my pulsar 150 dtsi...

Intsalled K&n on my pulsar 150 dtsi...
Sounds great....
But there is a humming sound from the engine.. mechanics say that it is magnets sound... but I doubt it as I have changed the complete magnet assembly...
Also FYI... engine was opened once when the earlier magnet and bearings were out of condition... mechanic thought it was a engine seizure and opened the whole engine for it
.....

[PRANAV D]

@abhijeetbuzz great! but did you upjet the carburettor after installing K & N? If not then u should as soon as possible.

[Ayson]

@Anupdas


A leaner mixture than needed prevents the engine from cooling sufficiently. The piston, cylinder and valves are cooled to a large extent by the fuel in the charge. Think how just the fins around the cylinder can cool the super hot valves or valve seats sitting in the head?


Like you said, an over rich mixture is a waste of fuel. Just like that a lean mixture is a waste of air!!! I'll make sense. Imagine the ideal mixture of 14.7:1 (air:fuel by mass). Any air more than 14.7 would mean fuel less than 1. Now you have created a situation where there is unnecessary air in the cylinder. The oxygen in that air is useless because there is no fuel for it to react with. It takes up place in the cylinder with no useful purpose.


What you said would make sense in higher altitudes. But you are not really changing the mixture. When the settings are adjusted for change in altitude, what we are doing is, reducing the fuel supply to accommodate the reduced air supply so that the ratio remains the SAME.


I'm not sure, someone correct me if im wrong.


Now, i have some questions about the aftermarket free flow air filters. When anybody wants to upgrade to one of these, the first advice given is to upjet. I have read in many posts that a jet of a higher diameter is to be used. I understand that since you are letting more air in, you should also let in a proportionally higher amount of fuel to keep the ratio constant. But here are my questions.


1) In a carburetor, the throttle handle controls the butterfly valve near the venturi. The more it is opened, the more air is let past. Now as far as i know, the fuel is drawn through the jet into this airstream by the low pressure created in the venturi. The more the throttle is opened, the faster air flows, the lower the air pressure, and a proportionally higher amount of fuel is drawn. So, Eg. : 50% open throttle, would create pressure X in the venturi with stock air filter, would a free flow filter cause the air pressure to not drop to X, due to lower air velocity, hence drawing less fuel due to lack of suction?


Or, will it be the same drop in pressure since the throttle position is the same and air velocity is the same? What exactly causes the mixture to change without upjetting WRT carburetor workings.


2) Why upjet? Why cant we just use the volume control screw?

[Anupdas]

@ Ayson

Thanks for the reply bro, when I asked that question I didnt know the working of Carburetor. I didnt knew that its the amount of air which regulates the fuel. So once its set lean it will remain lean, even if the air flow is reduced or increased.

Its still not clear to me how the lean mixture heats up the engine?

And about the need for upjetting ? When we increase the air flow as by adding the high flow filters the venturi wont be able to provide as fuel as required. So that explains why people are increasing the jet size and then doing the tuning.

[Ayson]

Reasons why engine running on lean mixture heats more:
1) Craburetor gives out a charge of air and fine fuel droplets. Fuel in the charge cools the valves, valve seats, cylinder head, cylinder walls, piston head, etc by absorbing heat and changing state to gas. Less fuel in the air, less cooling.

2) An exact mixture gets all the charge burnt, producing more expansion and heat. Combustion of a leaner or richer mixture will produce less heat, but inside a cylinder a richer mixture would burn cooler, because the extra fuel absorbs some of the heat.

3) Without cooling from a rich mixture, all cooling would be dependant on the cooling system.

All these reudced cooling would compound, to finaly make your engine run hotter than desigened and seriously damage it in the long run. Pistons, valves, valve seats, spark plug electrodes, all will suffer damage. Then the engine would start detonating or pre-igniting or both, and this would just multiply the damage. Even your exhaust manifold and silencer will be at risk.

Now my question. When switching to free flow, why do we have to upjet? Why cant we just use the volume control screw instead?

[Ayson]

and a bump to the top

[nilayworld17]

want to install a air filter in my apache rtr 160.
can anyone tell me that which one is best for apache???

[psr]

K & N is it good ?

Dear XBHPians alot of interest had been shown on changing OEM AIR FILTERS TO K&N. Here is the link to clarify about K & N and its performance

K&N air filter or OEM, why OEM is better

[Sunny]

Topic Merged

[RogueRider]

Remove the weeds

Kn filters will bump performance if the bike/car is already modified. On a stock bike the performance is negligible, though sound increases and it misleads the rider into thinking it's faster.Since the airfilter is bigger than the stock airfilter it sucks in more air which it supplies to the engine, since it's bigger it might also suck in more dust particles. Cleaning it every 2-3 months will keep the filter from getting clogged and performance will not dip. If carburettor is upjetted after kn filter is installed more power can be experienced. My own experience!

some people are running an anti kn campaign here, in the name of spreading awareness they're bringing disrepute to a company whose products are used by millions. I wonder why such people cannot and take the fight to kn, prove their filter is harmful for the bike and make the news official. Instead of confusing people who actually want to buy kn filters...

defamation case anyone

[RhythmRana99]

K'N in yamaha R15

hey friends my R15 dealer is offering me K'N RC1060 to fit on my 1400km old R15 to increase/change the exauhst note. and lil bit increase in accelration too. but when i asked him will u increase the fuel flow he said jetting is not needed on R15 as it got Fi. but I read somewhere that R15 ECU is not closed loop. which can self adjust fuel acc to air provided but i'm confused by the dealers wording as he installed many K'N filters in R15's and i also talked to owners they are satisfied with it and no problems. so now the web and real life is confusing me please can you help me. i love the exauhst note of R15 after installing K'N and i don't know now what to do....??

[Killer]

I see you've already seen this - http://www.xbhp.com/talkies/desi-bik...airfilter.html

So what more do you need to know? You can continue to ride your bike, it will run lean and overtime that wont do your bike any good, or you can get the CO adjusted. Simple

The dealers dont know jack shit about the bike

[RhythmRana99]

that is what i want to know how CO or fuel can be adjusted because svc people are not doing it so how to adjust it.

[Killer]

If they are not doing it, you will have to go to someone who has the handheld device and who can do it for you. If you dont know any such person, then take a call whether you want to continue running the bike the way it is or go back to the original filter.