What is engine power of Bajaj Pulsar NS160?

Get you fuel injectors checked. If mechanic suggests replacing them, first try using fuel additive (I suggest Liqui moly fuel additive), use 80ml pack in every 5-10 litres of fuel. This will clean the fuel injectors if they are any clogs. Also use oil of synthetic 20W50 if you regularly ride your bike for 25 or more kms and if you live in a hot climate city, if you live in average hot and cold climate city, use synthetic 10W40 oil. With every oil change, use oil additive (again liqui moly oil additive will be one of the best) and change oil filter at every oil change if your bike has one. Use engine oil flush as well before changing the oil. These additives works as medicines to your bikes health. Change fuel filter. Clean the Carburetor. If still the problem persists. Check your clutch placements and tune it while on double stand with your mechanic. You may have to test ride as well few times before you think your clutch system is best in stage. Also, you may try changing to a good battery brand like exide in India. Before installing the battery you may check and take a short ride with the new battery to feel the difference if the problem was because of the battery. If nothing makes the situation better, ask someone experienced to ride the bike and check if the person is facing the same problem as you are, maybe you are just riding the bike the wrong way or maybe leaving the clutch too early. Again, if you still see the problem, replace the fuel injectors. If you still see the problem, then the engine is probably damaged already. Try the steps above and InshaAllaah you might see difference.