I have TVS Victor GLX 2004 model and it crossed 57000Km plus , my bike gave mileage about 60km/l constantly, but after the 57000km reading, i have noticed some sounds in my engine which is not usual in my bike before and i indeed to change the engine oil after every 1600 Km after that my engine performance very low and overheated also 50% of the engine oil is burnt.Also misfiring is major problem in my bike. The mechanic said me that the problem is with the core and the piston also some parts to be changed in my engine and for misfiring he said me to check and rewinding the coil in starting coil or running coil...... Can u tell me whether its all true and correct wat the mechanic said to do and its worth to change the piston and core .I need the to know how much does it cost and is it worthy to change for the 8yrs old bike, if so can i get the 60km/l mileage again and also the performance......please help me......

Motorcycles - TVS - Victor GLX