Don’t use yellow or clear Tygon type lines or they will melt off. Use a black rubber fuel line. 3 x 5 or 3x5.5 MM is perfectthat is it! The crack was on the bottom of the line, I am going to try to replace it tonight. I am getting 7/64 od, and 1/8 id, and I may see if I can get something at the local mower shop or home creapo.