...
thank u thank u...

Prince

1 more point..
dude i had a small discussion with my friend about the issues you face...
Upjetting was the repeated answer... the same possibilty for your over knocking issue.
Dont worry over it, try a higher jet, a rich mixture wouldnt harm your bike as the present lean condition does. try it and you will understand.
DONT SPOIL YOUR BIKE AND REGRET LATER... knocking is not a small issue.
and Remember you are on highway on high speeds...

@ prince

Please put up a picture of your spark plug in closeup (macro mode) without flash, to let us know your carb's state of tune.

knocking problem can be clutch related too.

Worn out engine bearings can also cause knocking. I can't figure out how's your engine running lean, as you always get it tunned for max performance...

@ kb100
@ pavanchirmade
@ ARNandal
@ Honda CBF
@ psr
@ Nanotechnology

thank you guys for helping me out........here are the updates...

1) yesterday i checked the spark plugs, they are prefectly fine and had greyish white colour, which shows that they are fine and everything inside combustion chamber is ok too. both the spark plugs a firing. checked that too.

2) engine oil level is ok too.

3) cooling fins are also clean.

4) yesterday replaced the breather pipe, though it was ok and not choked or anything else. since i had never changed it.....so replaced it, 13 bucks only.

5) i had mentioned earlier about spit test as i have read it on xbhp only that it is a way to test engine temperature. well even if it is not a good test, regardless of that .........engine does overheat.

6) clutch plates are also fine as i have replaced them just recently. and it didn't solve the problem.

7) my connecting rod is a stock one.... @ ARNandal. in fact everything is stock except DC wiring, stator rewinding and HID.

8) how to check whether engine bearings have worn out--- @ Honda CBF, do you mean crank bearings or camshaft bearing. i think both are ok since they were checked at the time of engine reboring a month back.

9) well, yesterday i got my bike examined by ASS and my favourite mechanic.....both said, it is not knocking but piston noise, which comes when engine is loaded and since i live in hilly area, that sound comes most of times as in hilly areas engine is more loaded. i am a bit confused on this.

10) yesterday, i also checked A/F screw of carb, it is set at 4.5 turns. now you tell me if its ok or wrong........???

11) so now i need to make a temperature sensor.......is this LM35 easily available, and where to mount it and how. shall i stick it on engine block body, if yes then how? and what is the correct temperature that engine should run. and what is the temperature range of LM35.

guys suggest......

Answers in bold

I've ridden a guys pulsar150 classic with its worn bearings (both crank & cam) bike used to overheat and drink oil.
Symptoms of worn out bearings are:
*cold start problem
*grinding noise
*loss of power & mileage
*low oil pressure

@honda CBF: out of all the symptoms you have outlined, none exists iin my bike except low mileage, but that is due to my riding style.

@psr: in the spark plug troubleshooting guide, it is shown as greyish white to be perfectly normal condition (mentioned in sparkplug thread in my signature). r u sure it means lean AFR.

regarding carb screw, can you confirm if it should be 2.5-3.0 turns??

and what should be the ideal temperature of engine.

pl check the reed switch mounted on carb. it is connected to cdi unit. disconnect it from cdi unit and check. it should show 0 ohms(short) in throttle closed position and open ckt(1) from 1/2 to full throttle position.

i checked inpulsar workshop manual......it says carb screw should be 2.5+/-2 turns out.....and mine is at 4.5 turns. pulsar carb screw is petrol control screw, the more we loosen it, the more richer the AF mixture becomes......so my engine should be running on rich mixture.

+1 to that.
@Prince: i think 4.5 turns is pretty on richer side (i won't advice going more than 3.5 turns i.e. 1 Turn more than factory settings)
but your spark plug says different story. Try upjetting your main jet.... And waiting for your engine temp at different intervals of riding

Are u referring 4.5 complete turns? A complete turn is full rotation of 360 degree.. Manual says 2.5 complete turns. 2.5 to 3 from completely closed position is just perfect..

manual does not say 2.5 turns, it says 2.5+/- 2 turns i.e. 0.5 to 4.5 turns. mine is set at 4.5 turns, so it is on the richer side, and plugs are white. any guess? how this happens.

Either you are using hotter plugs or there is leak in inlet..

i am using standard bosch UR3DC, in fact i was trying to get a colder set of plugs........but not able to find.

if there is a leak in inlet then engine sound will change to somewhat like it comes when you drive with filter removed.

I AM REALLY CONFUSED BIG TIME..............

Prince...

Itz not the no: of turns that decides the mixture to be rich or lean...
P150ug3 needs a 115 main jet at stock condition and using a 90 size main jet, getting 5 full out turns and looking for a richer mixture is not possible...!

4.5turns outwards on a stock p150 is on the richer side, but itz not what your spark plug shows... your pulsar is now grown up and need more milk to drink... throw the nipple in your feeding bottle and add a bigger jet in place...
try it,too rich wont harm your bike, sometimes you would shoot out the issue else you would rule out one more possibility.