the crankplugs as you suggested. A little black ichor dripped out of both plugs. It is a thin, black liquid that smells strongly of gasoline. I checked my transmission oil level next and it was still level with the overflow/level check screw. So I am not sure yet if it WAS transmission oil coming out of my leaking, dry, cracked muffler connectors. I was running premix and had the oil pump lever fixed at maximum oil delivery and it was pumping pretty fast. It cleared the lines of the old brown oil that was in them quickly, then the delivery lines were full of new blue synthetic oil after a few air bubbles pushed through. It seems to me that I was giving the crank a lot more oil than it wanted at idle, so possibly the black liquid was just a burnt 2stroke oil and gasoline mix. Thanks for the advice Paul and Niel, I am crossing my fingers that it isn't bad crank center seals. The left carb had way too much gas spurting out of the overflow tube, so I know something is wrong in there as Niel suggests. I've got a spare set of used carbs that I am going to install after a thorough cleaning and check. Also I am going to get some new muffler connector rubbers if I can find them.