If you are finding the oil around the exhaust system, then it is most likely coming from the oil metering pump. No need to throw your motor away man, just fix the little part on it that is causing the issue and you'll be all set.
The OMP is located on the front bottom passenger's side of the engine. It will have a rod the runs up to the carb, along with a couple of lines to carry the oil that is injected into the carb. A very common place for leakage.