I did a fuel line mod on a quad & it worked well. I have another quad which is a 70cc Zei - like a Zstar. Carb inlet is less than 5/16 ", like 1/4 or metric of that size. Fuel tank outlet accepts a 5/16 without a prob. What can I do here besides a different carb ? Also where do you get a 5/16 fuel line shutoff valve to replace the petcock - tried about 3 places.