I am in the process of re-assembling the right side after a crank seal replacement and have a couple questions. It appears from the parts I have sitting on a rag from last week's disassembly (and I don't think I've lost any) that the order of re-assembly has the crank seal going in, and then the crankshaft starter sprocket immediately thereafter with nothing in between. Question, then, is what keeps the crankshaft starter sprocket from rubbing against the crankshaft seal? Or worse, rubbing up against the case? Nothing? Is it a non issue? Maybe the offset of the starter's sprocket keeps the crank's starter sprocket in line and off the case/seal? Curious.
Also, how much slack should be in the starter chain? Mine has so much that it actually contacts the bottom of the case. Is this typical? Should I shim the starter back a washer or two's distance? Is it even worth the effort? Pic of the area where the chain contacts the case is below:

IMG_0604 by rzgkane, on Flickr