I have a CBR 250R 2014 model year, run for 24500 kms only. I am facing a strange problem with my bike. When I put the bike in idle and twist the throttle suddenly, the bike sounds like knocking kek kek kek.

I went to my mechanic and show my bike he test rode it. He put it in idle in neutral and twisted the throttle suddenly and decelerated the bike. He pulled the clutch lever and again did the same thing. The sound is somewhat better when pulling the clutch. The bike never sounds bad when kept in idle. Only upon sudden acceleration it sounds worst.

He told me clutch housing is the culprit. The same day he changed the clutch housing and the primary gear. Clutch plates is also replaced as there is no pickup. The bike sounds good for 2-3 days and after that the second problem started.

The bike knocks upon acceleration sounds like a kodokodo. Also, the bike struggles when climbing uphill. I cannot accelerate suddenly because of this issue and the bike has no power .The mechanic told me that he thinks it is a loose piston, please help me. Is it going to be a crankshaft problem or a loose piston? What about the estimate repair? Will it run like new after fixing? I thought hondas are reliable.