how many tanks have you run through it?
on a bench youll need 2-3 tanks before touching the needles,or in a car 5-6 tanks , top end is usually extremely rich , in some cases ive had to turn the top end in 2-3 turns after run in process to get it close,
all motors are tight when new and the all make that tight sound for the first few tanks
ive had and use sirios and have never had a problem, there the best motor by far