I'm about to take my bike in for a checkup, it's been a few years of doing the regular stuff myself but I like to get it in the hands of a professional every once in a while.
Imperial asked if I needed a valve adjustment, and honestly I don't know. The bike has over 80,000 on it, I've had it for about 15,000km and haven't done one. Didn't get any maintenance records from previous owners. The bike starts and runs fine.
So, are there any indicators l'd look for to know if it needs a valve adjustment?