Chainsaw Repair

Got the O ring (which is more of a short piece of tube) amend the oil flows correctly now. 

Had to replace the entire fuel cap.   I could not get the gasket alone, but at $8 I can be a sport. 

Can the ring that the chain goes into that slides over the sprocket (?name) be placed on either way?   I placed it with the numbers designating pitch on the outside, but the owners manual shows it the other way-the clover leaf pattern is facing out.  Is this reversible, or should I disassemble and turn it around?

This saw is ONE MEAN MOFO by the way.  I have the factory 20" bar on it that seems ridiculous.