My tank is vented to the atmosphere, I have the return line (from the primer bulb) blocked off, there is only one line from the clunk to the fuel inlet on the carb. I have leaned it out some and it seems to be better inverted, still not "right" but at least it doesn't try to quit, just loads up a little.
[quote]ORIGINAL: Gismo

Honda says that it is a overflow/return line and does not pressurize the tank................... Also, is your tank vented? Something to check...

Gis