Gear problem hero bike / 3rd gear is not working

gaadi ki sabhi parts theek hai sirf teen number wali gear nahin kam kar rahi hai teen number gear dalne se bahut jyada gadi ki engine se awaaz aane lagta hai aisa lagta hai ki chamber fat jaega to main aapko batata Hun ki kisi number ke gear ko aasani se kaise theek Karen aur isame jyada kharch bhi nahi hota ❤️❤️❤️