Hello. I have done 6000ks in my honda unicorn. But from day 1 i have some problems with gear box and sudden pickup.

Problem 1) Some times there is a sudden pickup and drop in speed just for a sec, It feels like you have given a full throttle and brought it down in a second.
problem 2) Many times it shifts into neutral when i shift 1st gear to second gear. And also have problem in top gear (5th gear). some times it comes to 4th gear while travelling in 5th gear. 3) some times it feels a matalic sound comes from engine as if the some weels are slipping and also a other a sound comes out (like when you wrong shift gear in yamaha you get a sound right). 4) Also got another sound from engine yester (sound like a stone has hit the engine) I feel like the sound has come from bore of the engine. I have already took the bike to silicon honda bangalore 4 times in this month (feb 2023)and in the fourth service the found out that the gear-shift is bend and have changed it. But still no benifits. Have given it yesterday again to them for the 5th time. Dont know what do.