Originally Posted by Truckracer

The easiest cure to insure constant fuel flow to the engine is to use a genuine Walbro in tank felt filtered clunk. Don't use one of the knockoff clunks as some have been known to shed fibers. This stops any bubbles from getting into the fuel line and it will insure you pick up every drop of fuel the clunk can touch.

Gasoline fuels don't normally foam excessively or hold bubbles like glo fuel does so foaming problems are rare with gas engines. You might make sure the tank floor is solid in the airplane and check to see the prop and spinner are well balanced and running true. Maybe change from zip ties to Velcro and adding a bit more foam under the tank might help. Maybe the particular oil or gasoline you're using is prone to foam. Does it foam if you shake the fuel jug?