I bought this engine at a flea market two years ago and it did show signs of being overheated with the discoloration of the paint around the two spark plugs .But now with extensive pulling it will not run although it sounds like it wants to.I took a compression test on each cylinder with a little oil in first and got 30 psi on each.Is it possible just to replace rings and gaskets and get by.I have plenty of spark and have cleaned out the carb. The year is a 85? and the model # e6rcrm .any tips would be appreciated and where to buy parts.