My bike was sat for years. I never bothered with valve clearances, except checking them. It's now had an Italian tune( I love that term) and only now after a thousand + miles she needs shims oil and filter, sump off and oil pick up check. then it's time to see what it can do oh and new pads all round. Well that's how I've allways done it where shims are involved cos of the expence of the shims and the time it takes.