Check any hoses and the fuel line for cracks that open up during operation. The fuel pump creates a partial vacuum in the line to draw the fuel from the tank and will suck air through any pinholes and/or cracks.

I had a fuel line that rubbed on the frame enough to wear through and allow air to be sucked in but not enough to make a noticable drip. The fuel line and frame were 'damp' but no fuel was dripping.

So, check the line as well as the fittings and hoses for pinholes, scuff marks, and cracks.

Hope this helps.

52 Ted

illegitimi non carborundum