Are you intending to dispense the beer over an extended period of days? If so, your problem will be off taste more than foam. Bud Light is not pasteurized and must be kept cold at all times.
Also, what type of tubing did you use? Vinyl or polyethylene? Did you use any 3/16" ID behind the shank?
Scott Zuhse, Instructor
Micro Matic Dispense Institute