Honda BF115A, BF130A Outboard Motors Shop Manual., Page 200Get this manual
HONDA BFI1 5A-130A
8) Apply soapy water to the lip (shaded part) of the spark plug tube seal as shown9) Clean the cylinder head mating surfaces with shop towel or equivalent materialAlign the spark plug tube and the spark plug tube seal by inserting the return tube into the hole in the mounting case, and install the cylinder head cover
Insert the spark plug tube into the spark plug tube seal with care not to cut or turn up the sealAfter installing the cylinder head cover, visually check the seal for turn-up or damageWipe up the excessive soapy water that oozed out from the lip of the spark plug tube