I have a 115 Yamaha that went in for its first 100hr service and came back leaking oil after the boat was stopped. The oil looked like it was mixed and only dispensed out of the top unit drain once the motor came off a three of four hour troll. On a revisit to the shop the oil leak still can not be located and still continues to happen when the boat is shut down. I have heard that this may be coming out of the dipstick by other sources but can not be sure.