1. coz you need a new inner lining for the new piston and to get that the only way is to rebore. Now after reboring the size of your combustion chamber has inc from stock so you need a bigger piston. Bore wont be for 5-10cc, its a very marginal increase.
2. An oversize piston for any specific bike is slightly bigger in size. you can get it for any bike, you just need to know where to look at. For 180 classic I used a zero number piston, It was usha make.
In delhi they are easily available in karol bagh market.
3. CC is inc marginally 1 or 2 cc max. Performance gain is hardly noticeable. But you will surely get better performance coz you are gettn a complete overhaul.
Mileage drops. Mine is giving something bw 32-37(May be coz i have shitty alloys and a 120 rear).
4. No, 180 classic and dtsi have same piston size, but even if they dont, it shud nt be a problem coz 180v1 parts are very easily available.

@Harmeet: Thanks, thats been a handfull information.

1. How much does it costs to rebore?
2. How about using p200/220(dtsi) block and piston?
a. Would that work out if yes, any suggestion on entire process?
b. Any long term issues?
c. And what could be average cost?
3. Would it be smart and logical to replace the entire engine with higher capacity engine, like 400cc or 600cc. I can see few available on ebay?

1. Should not cost much coz its just a simple drilling job. I dont know the exact price but it should be done within 1k.
2. You know what, I had the same idea before going for the overhaul. But I wont advice you to go for 200's cylinder kit, I heard its an easy job on any 180. But then dtsi would be a problem coz you have two plugs in 200 where as your bike has 1 and the CDI is diff too. So If you want a hastle free job and dont intend to spend much(I mean above 7-9k) stick to the 180.
2(a) May be...I dont know
2(b) One hellova dragster.
3. NO, Pulsar 180v1 has a horrible chasis, the swingarm is too short and the shocks are made of wood. The entire set up is not capable of handing 400's weight and power. The engine would not be a direct fit and I would require some cutting and welding of chasis.

Take my advice, go for the 180 complete kit if you can. Else get a overhaul from a good mechanic.
If you want a performance mod. Go to a good tuner after the run-in, replace the lower jet by 1 no and upper by 2 and an NGK iridium and get it tuned , that should be more than enough (NO K&N PLZ).

Do not rebore

I would not at all suggest the idea for rebore because reboring is done using old worn out machines and stupid mechanics and once the alignment with the original bore has gone,your engine has been screwed up for sure.It will drink oil,vibrate,give less average,smoke and what not it might affect the bearings and crankshaft too bcoz of the misalignment.
To save 1000 rs now you will borrow lots of headache,lack of reliability later.Not all are lucky to get there work done nicely as needed.Infact in most cases the engine gets screwed up.I personally know of such cases.

Instead buy a piston-block kit with new piston,rings,cylinder block.Also change the valves and valve guides or get the valves lapped if they are leaking.You might need to change the engine timing chain,crankshaft main bearings and connecting rod small end bearings.
We do not open engine every day so research for a good mechanic,purchase all the new parts at once and once the job is done the bike will nearly have a new engine with the earlier power,smoothness and fuel efficiency back.

Guys, you all are so damm smart, it makes me feel proud of the community. Belive me no ordinary guy would ever be able to even think on the lines and depth that are given in here. I got good friends online, all i wish if i could have an online mechanic, to whom i can upload the engine and who could work upon and send me back via mail and i could pay him via paypal (i know real world is much better than virtual world, but things get done faster in virtual world).

I have taken your inputs, now the tough part begins, search for a good mechanic, I will try to get a smart ass out from Service Center if possible. So probably on weekends he could work on my machine. That way i will be able to get a smart guy working for me and allowing me to be there all the time, this might give a special bonding too, and would make me somewhat knowledgeable in open heart surgery of bikes

I still ponder, wont it be nice to bring in second hand 400cc/600cc heart as it doesnt cost much. Dont know if its possible so source locally.

@Mods: Could you rename the thread to "Pulsar 180 Classic to Pulsar 220 Queries"

I am thinking on lines of doing heart transplant and to get bigger one. Also I think a lot more experienced guys who have gone though the process would be able to pour in there suggestions.

Thanks
Vinit

If you think 5000 is a lot of money then what are you thinking about 400/500cc. Where will you get the engine? Anyway someone has already outlined to you why you shouldn't consider it.

You can opt for a 220 bore/piston kit and 32 UCAL carb and maybe K&N too.. along with a FF Exhaust. Change to dtsi swingarm and shocks too. Tighten front shocks.

Anyway. What you need FIRST is a good mechanic. So I suggest you look for that, talk to him first and if you have queries after that, you should ask them here. WHy dont you mention where you're from so someone can guide you further

I found Rs 5000 to be on higher side for the task in hand.
For 400/600cc engines, i already mentioned i am eyeing on ebay.com and ebay.co.uk, they have plenty of them from R6 and other similar bikes from 07/08 models

I am open to investments for performance upgrades, if those are sensible and reasonable.
Yes, I am in touch with a some sensible heads, they have there share of knowledge but none of those mechs have ever done this kind of surgery, thus before i plunge into I am trying to gather the needfull first hand information from guys who have already taken pains and have learned there lessons.

Oh sorry about that.. I didn't realize you were trying to put a Yamaha R6 engine into a 2001 Pulsar chassis. My bad.

Incidentally I have plonked a 220 cc engine into my classic 150 chassis but that was the limit of my intelligence.

@Cesar: As I said i am exploring options, so yes even thought of converting to electric motorcycle which kicks out any 600cc bike, but given the cost involved I have to push out But one day i will get it done too

Its nice to know that you have taken the same route, and I would highly appreciate if you could kindly share your experinces and guide me through the process or else if you have any thread here on xbhp that contains the entire discussion then kindly point me to same.

Anyone still there???

Hmm it seems this thread has been stagnant for a while now but i have a query...
@viny:i too have the 02 model 150 classic..and it shows the same signs as ur engine once showed,,for eg. no compression,vibration,overheating,drinking oil...
I guess u have overhauled your engine....

So it would be really helpful if could describe what you did to u bike,,so that i can try it out,,,,
Any advice is welcome...
Thnk you...