WAAAYYY over primed corny keg!!

[bradknows]

I just finished primary fermentation on my first batch of beer, (my attemp at a Guiness clone) and thought I would prime the corny with some maple syrup for kicks (and because I can't get beer gas in my area). Here is the problem. I had it in my head that I needed about 1 cup of syrup to prime the keg, and the bottle I used looked like about a cup, so I boiled the whole bottle in some water, primed the keg and stuck it in the bathtub in case it sprung a leak. Then I decided to research and found that I should have used about 4 OZ instead of 24OZ of priming sugar. I immediately sanitized a keg adapter some hose and an airlock and connected it to the gas side of the keg, and got a gusher of glorious stout all over the bathroom. It is still bubbling vigorously about 2 hours later. My question is: When should I stop venting and allow the keg to pressure up? And/or should I just let it finish bubbling and then prime it again using the correct amount of sugar??

[BDawg]

Fun stuff-

I'd let it re-carb now that most of the pressure has gone out.
There's still plenty of CO2 dissolved in solution, and it will equalize itself in the head space if you just give it a few hours.
At that point, try to pour a LITTLE again, and let the keg depressurize if it is still too carbed.
After a few rounds of this, you should be good to go, and even if you overshoot, you can always just connect the gas and force carb it.

HTH-