I got spark, fuel, clean carbs, clean jets, oil pump's new and workin, fuel pump's new and working, compressions 120 in both cylinders and i can't keep it running unless i prime it. Please somebody give me a light of hope here! Is it a seal i cant see? Bent shaft? Something in the crank case? Head gasket? I've checked everything! Im about to just sell it for $400 just to get it the hell outta my garage!