A Yeah, Dave, it is normal for a new bike's valves to tighten up a bit. As the new engine is run, the valves tend to pound into their seats; this causes a slight loss of clearance and is entirely normal. For the novice, valve adjustment can be a little tricky, mainly because it does take some experience in using a feeler gauge to develop just the right "feel." Until you develop that feel, I'd suggest using what's called a Go NoGo feeler gauge, available at any tool supplier or auto-parts store, to set the valves. Go NoGo gauges are stepped or graduated. When the adjustment is correct, the first portion of the gauge will slide freely, yet the second portion won't. For example, on your intake valve you'd use a Go NoGo gauge that had a leaf stepped from 0.006 to 0.008. When the adjustment was correct, the 0.006 portion of the gauge would slide freely, while the second portion, the 0.008, would stick. As an alternative you could also double-check the valve using two separate gauges, an 0.006 and, say, an 0.007 or 0.008. If the 0.006 slips in, and the 0.007 or 0.008 doesn't, you're good to go.