Putting a bigger carb will obviously hamper your mileage. I suggest you buy another carb of the same make and get it fixed. If you really want to go for the bigger carb, ensure you get it fit and tuned by a good mechanic. Unless you get the air/fuel ratio and the tuning right, it wont really help you at all.

Hello sandeep,dont mind im confused,no one here who can resolve my problem,my doubt about my pulsar150 classic,my p150 classic carb done its duty!time to change it thinking to switch to mikuni29 (pulsar 180 carb)in my 150,im sure it will increse power torque but want to hear from member who have clear idea or have done it before.