The typical "F" series muffler, round steel, bolts to an aluminum muffler plate with 3 bolts around the crankshaft, with a crankshaft "support" plate.  It is just a pressure seal around the outside edge.  Other than cleaning the mating surfaces, does any one use any type of sealer when refurbishing and decarbonizing, in replacing the muffler??
	
		
			
		
		
	
			
			 
				 
 
		 
 
		