the cover for the flywheel it keeps hands away from the fins, that and it is for cooling as well. the flywheel is in the center, spins all the time the engine is running for cooling, spark, alternator, the cover is a thin metal thats held on by about four bolts for a single cyl. ten. you'll have to take the starter gear cover off first before taking the shroud off. maxlife will do good, Mobil 1 as well, use Mobil 1 myself, briggs engines just run good on it. i'd also pop the head off, and clean out all of the carbon in the combustion chamber while you have the shroud off. as for cleaning it up inside.... you can use AutoRx to clean it up inside, mmo, etc.