I'll try posting pics of cracks and plugs. Area shown before cleaning, after cleaning with JBweld applied, another area cleaned without JBweld, area shown after run with blue chalk shows crack and an area of crack, plugs and my finger with fuel from plug hole area. (I guess plugs not tight...
I bought used '82 Merc I6 90 HP last year, have done all needed to get a stored motor back up. Went to lake, thought one cylinder was down but all have good compression, fuel and spark. Just starting at top carb mount and angling around the enrichner valve mounts there are "Hairline cracks"...
