For pulsar's best performance????????

• Bajaj Pulsar 150 cc Price in Delhi: 60,000/- Indian Rupee
• Bajaj Pulsar 150 cc Price in Mumbai: 68,000/- Indian Rupee
• Bajaj Pulsar 150 cc Price in Chennai: 64,000/- Indian Rupee
• Bajaj Pulsar 150cc Price in Bangalore: 65,000/- Indian Rupee
• Bajaj Pulsar 150cc Price in Hyderabad: 64,000/- Indian Rupee
• Bajaj Pulsar 150cc Price in Kolkata: 65,500/- Indian Rupee
• Bajaj Pulsar 150 cc Price in Pune: 62,000/- Indian Rupee

Hello,
You may have broken gasket /seal in your carburator,or stuck floating valve. Dismantling your carburator to justify which parts is in problem. You need a good screwdriver to dismantle your carburator.

There are many specilist who can modify your bike to you need and budget and you must get in touch with one of them in your city.
Make sure that the alterations do not affect the techincal speccifications of the engine and bike to give a lower performance but should be made only to enhance the look and performance.
also the budget you have must be moderate to the cost of the bike as the resale factor should be considered or a newer bike with bettter features can be looked into.
Hope you understand my tips.

pulsar 150 cc 2010 modl new this bike gives a milage og about 40 to 45 km per litre..

8000 rpm is the rate of pulsar 150cc

You are rightly going, go ahead and take precaution to keep constant speed. After 2000Km you can run for getting optimum milieage from it.
I had used to run Pulsar and Unicorn and served 3 years in Honda Service Department. 
Avoid much using break and over gear transmission will also help you in maintainging a good mileage.
Thanks