US 41 Foaming
 

I am new to gas this year. I just maidened my new Giant Aeromaster with a US 41 and the stock ARF tank. It has a 2 line system with a Sullivan fuel valve in the supply line for fueling. It uses a heavy brass clunk for fuel pickup. I had problems with inconsistent running at higher rpms. I decided to run it at home with the cowl off to set the needles on the carb. While watching the fuel line, I discovered that although there are no problems when idling, the fuel foams like crazy when I advance the throttle. I'm pretty sure it's foam coming through, not bubbles from an air leak.

I did a search of threads in this forum and found advice re: padding the tank, felt clunks (with debate). Here's my dilemna: The stock tank is one that fits through holes in the formers and is secured via rubber bands in the back. I can see how it would transmit a lot of vibration, but I don't think I can pad the tank without going to a smaller or different shaped tank. Should I go ahead and do that or try a felt clunk first? Which do you think would be more effective?

Thanks,

RE: US 41 Foaming
 

The Walbro filter clunks are a very goog idea regardless of how a tank is mounted or what type it is. Gas is not prone to foaming like glow fuel but sloshing with any liquid can be a problem at times. The felt clunk goes a great distance in balancing that out, plus it's heavier and stays in the fuel supply better. Not to mention exit filtering. The felt clunk eleminates the bubbles in the fuel line caused by vibration and provides a consistent fuel supply.