I'm new to the site and this may be a stupid question, but, I have an old 1990Sea Doo GT (keeps me off the streets at night). The service manual lists the MAG side carb as part number 270 500 072 and the PTO side as 270 500 072. The shop manual just lists them as Mikuni Diaphragm. I don't think the carbs are available. How about reuild kits? Is there a direct replacement?