now my question is:
SHould i go for an upjet or just revert back to my stock filter? need your views

do you really want the K&N installed?
if yes, find a jet 10 no greater than your existing jet and then check if engine is running lean or not (plug colour should be light brown)

if you have slightest concerns about engine life, remove K&N and install the stock filter...

The castrol dealer once suggested a 20w40 grading Tractor oil for Pulsar(in Coimbatore). SO you mean to say that i can use it on ???? GTX series is for cars.Kindly recheck Castrol India - Motorcycles

If you want more power...remember " No Replacement for Displacement "..nothing can give better power than a higher CC engine.
GTX is an oil meant for OLD car ENGINE containing high level of Zinc,phosphor,and other friction modifiers.
Castrol India - Passenger Car Oil

mister, you have done all negative things to your machine, Installing k & n without upjetting is a strict no no and above that i suppose the FFE you installed in your BELOVED bike is just Dalda Dabba type, i dont think its calculated or design as per engine specs.

Regarding all things you have done al symptoms you are mentioning, clearly seems a case of busted piston rings aka loss of compression, Changing engine oil at this much interval doesnt matters. I f you really want it to be alive i again, i suggest you to remove poopy k & n and that FFE and go for piston change or probably a new kit !

Rest is upto YOU !

I feel pity for us. half knowledge is worse than no knowledge. you got a K&N thinking that A branded product will do wonders to your bike but it is not so... brand is no guarantee for performance enhancement. you need a lot more than a free flow filer, up jet.

I had installed the K&N for similar reasons you had... but i learnt my lesson pretty quick and now almost every part of the engine is under the scapel for mods... and let me tell you, i always have kept the option of reverting back.. the engine is a very complicated assembly where every part is perfect for its mating parts so if you change one of them, you need to change all (atleast theoretically)....

just for a bit of insight, if you need to increase the intake capacity, the filter needs to be changed, intakes need to be tuned for optimal flow, carb needs to be ported (depending on state of tune) intake tracts need to be mdified, valves may need enlargement... and the list goes on till the point you go bankrupt...

remember, cheap and fast is not relieable
fast and and reliable is not cheap
reliable and cheap is not fast

K&N is not a bad product but it requires a lot of brains and engineering to put it to good use and when you do have that, you will realise K&N is not the only option...

consult Joel if you really need a good set of mods... better stilll, sell off the bike and get a bike that was made to be fast....

remember the engineers at BAL are not fools to not use the K&N

^^+100 % agreed

Go back to stock setting and replace any damaged piston rings, intake valve and you might have to check for any other damage to transmission or cluch plate due to non compatible engine oil, which means you might need to open up the engine too for safer bet.
Once you are back to stock setup, get the carb tuned for maximum performance. That should give you 50+ mileage and performance actually better than what you think you are getting now. (Its all your imagination that if you have K&N your bike will sky rocket!, it wont! Your bike with proper tuning can actually do better than that!)
Or you can sell the bike and buy an RTR180

thanks... my main jet is 107.5... which oder jets should i cange and by how much? please guide me.!

I am not paying that much heed to the engine life because last night, got dad's permission to get a new bike within 1.5L.... jus after my semesters end. yuppie!
I promise ill keep that bike clea n dont repeat the mistakes again

hahaha... lucky you that your dad is buying you another one even when you actually sucked out everything from your existing bike...

My dad only bought me a 0BHP bike (bicycle)... and then I bought four bikes till date, of which all three were clean when sold... The latest one (Pulsar) is something I am experimenting with but again ensuring that I dont screw it up big time...

Ride safe...

whoaaa !! guys, you all scare the shit outta me. neways i know i have done a mistake. but what do i do now? "LOSS OF COMPRESSION".... "DAMAGED VALVES".. "CHANGE OF PISTON"....."NEEDLE BOUNCE".... im just dead!!
kindly can you please enlighten the symptoms and remedies for these problems? as i dont have any idea, it would be of great help!

First of all, where is the filter mounted? directly on the carb or is it mounted inside the old filter cover?

if the filter is mounted directly on carb, you could be facing the problem of needle bounce. basically you need a longer intake pipe to dampen the fluctuating flow of air.

next step is to buy a p150, 180, 200 and 220 size jet - they cost around 50 bucks each.

then get a good O2 sensor and check its output after it has warmed up sufficiently... if possible, get a wideband o2 sensor.

if you cant get the sensor kit, install the p150 jet and check spark plug... if its lean, upjet to higher size else enjoy :P

its a k&n RC 1060. mounted on the carb. ok i will get these jets. Bdw, wt exactly is this o2 sensor? how does it work? where can i get it from?

Checking your post, i checked my spark plugs. Its just fine.!