I have an older Johnson sea horse 5-1/2hp outboard I baught today. It sat in a garage for 3 years and the gentleman said it ran when stored, but have a lot of resistance trying to pull the cord. I pulled the plugs and noticed the cylinders were gummed up and plugs had quite a bit of carbon on them, so I kept them out and tried again but still only got a bit easier to pull. And once again still has resistance. Any thoughts or advice on fixing? It would be extremely helpful. Or did I buy a boat anchor instead of a motor