I have recently acquired a 78 GL1000 in nice condition with 85000Km Compression is 170 even. Did carb work and synyc but it runs rough and coughs on idle. especially cold from start up. Plugs new . I noticed a lot of bubbles in gas line . A big fat one sits just below the gas tank and smaller ones come out of the fuel pump through the cone filter and into the carb . not a steady but intermittent regular flow of air bubbles. Is this normal or if not , what is the likely cause? I see no gas leaks around the clear hoses. I think first simple thing is to get new hoses and filters. The filters look new and clean but the clear hoses have turned yellow and are quite soft with no spring type clamps anywhere.We drained the tank to do the carbs and gas flows well through the shut off and the screen inside is clean. I'm hoping that if I can clear up these air bubbled it might idle better but I'm not sure if this is a problem. Any suggestions?