Well, I don't think that there's a leak from the carb to the manifold, as the guy who sold it to me gave me an O-ring to put inside the carb where it meets the manifold. I tried moving the clamp further up to tighten the connection at that point, but it hasn't made any change.
The only time I was able to get it to run for any length of time was before I added the oil that I thought I was missing. Is it possible that too much oil is preventing it from running? Now, it won't even turn over. The plug was a little wet (not dripping wet, but I could smell gas inside the plug hole), so I think I may have flooded the engine, but I don't have a torque wrench, or an air compresser, and am very leary of pulling the motor apart to dry it out. I've already broken an exhaust bolt, and I certainly don't want to break a head bolt, or over or under torque the head bolts.
FYI, I drained the tank into my gas can, sealed the gas can, shook it around for a few minutes, and poured it back into the tank to mix the oil and fuel a little better. If there is too much oil, obviously I can't filter the oil from the gas and start over...what do I do with this useless gas mixture?
By the way, I just used one of those handy online converters, and found that a half gallon equals 64 ounces. So, by toytime's scale, I should have only roughly 3.5 to 4 ounces of oil, not 8.