Query approved.

Prince since you mentioned clutch plates to be not the issue and good quality oil...

Possibilities for overload are high which can very much lead to overheating...
check the winding if it worn itz sure to take the load, try using more thicker wires (though i dont know the size you should go for...) for re-winding or try increasing the number of windings.

It is better not to run an overheated engine, it can lead to piston or crankshaft breakage... dont you have oil leaking, or did you rectify the oil seals?

And finally about the tuning, just check when your engine is switched off, of how many turns is the volume screw turned from fully tight.
Are you using K&N, how did you fit it and the jet size you are running on...and how have you provided breathing for the crank?
It would be much more helpful if we could know the oil brand in complete and your oil level...

and do you face knocking?... since you run on an increased piston size, compression should have gone high or is it normal, or did u make it up with anything else..

Obstruction or block in the exhaust also can cause overheating...

Apart from winding, running too rich on AFR can also cause overheating.
BTW what mileage you are getting? And does your exhaust gases stink more or comparable to any car?

guys......can a choked breather pipe be a cause.........coz i have never get it cleaned. does it needs cleaning or replacing once a while. can it get choked over a period of time.

my mechanic says that the fuel i fill is bad........can it be one of the causes.

YES, AFR which is too rich can cause overheating. Since your mechanic tunes for maximum performance this might be the case!
Well i have had to replace the crankcase breather pipe once in my old Unicorn (now sold), So check that out too!!

If crankcase breather is choked, it will make Your engine leak oil from everywhere else. Get it cleaned if not done for yrs.
And about smelling exhaust gases, i meant it should not give you burning sensation when you smell it for about 2sec. (smelling exhaust gases is hazardous to health).
1 suggestion: get your carb tuned for right AFR, not too lean not too rich.
SAVE FUEL SAVE NATURE SAVE MONEY

guys ........anything else i should check.......anything else.....can be the reason.

Prince...

1. I meant worn out coil can cause overload...
2. Dude i suppose Castrol power1 racing is FS 10W40. and castrol power1 is 15W40.
This use can be the main cause of your overheating...
Company recommends 20W50... 20 is the viscocity rating and 50 the heating thickness rating (in simple words)..
You can very much use less viscosity like the one you are using now...10/15, but the 40 rating cannot be recommended that too for pulsars... itz best to stick on to 50, anything more in this rating will reduce easy motion of engine parts since oil would be thicker than stock and would stick to walls..anything less the oil would easily loose thickness and become worthless.. this would definitely lead to overheating...(i got this information from Sandeep and MG_biker in Engine oil thread, check that out..)

So i would recommend Motul FS 15W50.. and i had somwhere that once you are on synthetics you have an option only to upgrade the S version like from SS to FS, but not to minerals or SS from FS, which can cause engine damage, though not sure but i found it somewhat reasonable...almost everything on earth has a character and so does habit.

3. Crank Breather pipe can contribute to overheating... itz just a hose right (am i right) that connects the crank to the airbox.. you can clean it all by yourself...

4. Bad fuel is termed so for itz high after burn carbon content... so carbon deposits wouldnt allow a smooth flow.... which can be a contributing factor...

5. as Pranav said check the AFR, but pranav only too rich can cause overheating right only ideal mixture delivers max performance.. a too rich one cannot...

6. Keep your palm near the exhaust out for a few seconds at 2000rpm.. check the smell.
if itz just the EXTRA fuel smell then itz too rich (remember that an ideal afr can have a small touch in fuel smell). but if you receive a pungent (not that of fuel) smell it can be the oil..
have a small 5-8 kms ride... insert you finger give a scratch inside (BE CAREFUL ABOUT THE HEAT)...
if you have purely dry black ashes (itz ok may have more carbon) or if you receive it a bit sticky wet or whatever your oil is been drunk, need to change or examine piston rings...

And about leaking oil, it can be purely because of overheating if itz from the oil seals (round rubber) found on the head near the spark plugs...

First check the exhaust for oil... if itz there.. check the piston rings..ensure proper seating else replace.
Secondly replace the oil (IMPORTANT)

And dude about the knocking it is due to over the limit compression, knocking in mid range and above are serious issues... and that too till 80kmph..
add one or more gaskets under the cylinder block that would compensate the knocking, but do it properly else oil leak again can be another issue...
Where you facing the same sort of knocking just after the increased piston mod, if itz a NO then your mech might have added an addittional gasket and that might be the issue if you find oil burning effects from the exhaust...
And do rejetting to a higher size try the 117.5 of p180 first then go for the 125 size of karizma. do this before adding the gasket... (itz just my guess...i hope am right... ask PSR NANOTECHNOLOGY KBR100 to advice...)

If rejetting doesnt sort the issue... try the gasket addition... hope compression prob would be solved

in any case either if the two still doesnt... you will have to upgrade the bore to next size or two.. anything higher than that would need machining (increasing) combustion chamber size

itz just sounds lenghty to read but not a complicated task...

but definitely would be one only if you leave it like this (cylinder and piston damage is guranteed).
Take it to the same mech...

Do you mean the Carb???? I have not seen a crankcase ventilation hose in Pulsars

i have just done reboring 1000 kms back. block, piston, rings etc are all fine. the problem pre-exists.

@phanikar:

No..you can see a hose going into the air box from that case where the whole head setup is mounted... the one where the alternator is placed inside. In my p180 ug3 itz near to the left side... the outlet hose/pipe that is near to the electrical connection outlet from the alternator...

I hope am right...

Prince

1. worn out means... a thick wire is a set of many small wires, so if there are few worn or burnt or cut.... which sometime you wont likely experience when you are riding or sometimes even when idling with head lights ON...

2. 20W40 for p150 is a surprise for me... i only know that lesser breeds of p150use this grade, but have not found anywhere about p150 on 20W40, even the last time when i was in the spares i found an article of p150-220 on 20W50 n other models on 20w40.
please make sure of this...

3. dont know about breather pipe getting choked...

4. The high compression issue still remains as a unsorted...