I recently built a kegerator with a sanyo 4912 and I hooked up my keg a week ago and when I went to pour it last night, the beer barely poured out.
I started with the pressure around 12 psi. With nothing coming out, I bumped it up to 15 psi for a few hours and when I went back, it still barely pushed the beer out.
The tower I bought came with 5' of 3/16" tubing. Using the calculations from this page, http://hbd.org/clubs/franklin/public_html/docs/balance.html , it seems like at with the pressure at 15 psi, the faucet approx 2.5' above the center of the keg and the resistance on the line being around 2.2 (according to morebeer.com's listing for their 3/16" tubing), that means I should need a beer line of approximately 5.5', so if anything, the beer should be coming out too fast and foaming.
Or the other answer could be that I have a leak, but if that was the case, I would guess that my 5# co2 tank would be empty after being hooked up for a week.
What beer line length and pressure do most people use with a sanyo 4912?