Is the carb hot to the touch? is it getting so hot from the manifold that it's boiling fuel out?
You sure the fuel line is not to close to the thermostat housing or close to the exhaust manifold?
It's hard to believe the fuel can boil at the filter from heat at the exhaust manifold, but I guess it can since you are seeing it. I wouldn't have though you can get that much heat from the riser.
Joe
