Dear PW experts the Khyber engine producing noise as kind of a whistle sound...the mechanic asked that PISTON PIN is loosed..n the other mechanic asked that TYPPET "chirian" need to be changed I changed but noise exist n another mechanic asked that valve is touched with piston....the engine is okay i mean no produce smoke no heat-up pick is also good. pls suggest the clue.
Thanks in advance.