Eileen

Hi. I have 2-1982 yamaha seca xs400rj's. Red and blue. The blue one is hard starting at times or when it is cool out,won't start at all.Cleaned the carbs ,changed battery ,starter ,plugs. Changed everything that would come off the bike (except the wiring harness ). Changed all those parts for the one on the red one (parts bike ). At the end of last summer, the blue bike would not start at all .As a last resort I changed the engine. Still is not right. The engine that would not run ,is now in the red bike ,with year old gas,.........and it started right up. What else can I try ?... What am I missing ??? Getting very disgusted ,probally going to sell them Thanks for any help !!!