A little understood and mostly unknown FACT......ANY gasser up to and including a 150cc 3W works just fine using the smallest ID fuel line...
Hayes Products molded neoprene is the absolute best....IMHO.....Or maybe not so HO
I just measured the fuel inlet fitting on the Tillotson carb on a new 3W 157..About .070....Big tygon tubing gets hard after a while and requires tie wraps to keep it on..The seamless molded neoprene will not slip off and is hard to even pull off..
Don't knock it if you haven't tried it