Sure sounds like coolant disappearing into the oil. When the coolant goes away, the temp sensor can fail to get enough heat to kick-on the fan, so that would be related to the low coolant. But you're talking about a big coolant loss. It's got to be oing somewhere...
07 Yamaha R6
07 KTM 950 Super Enduro
04 KTM 250exc- plated two-stroke
01 Kawasaki KE100
74 Honda MR50