Reporting back. I removed the clutch cover and cleaned the inside of the glass with kerosene then hot soapy water. It took longer to remove/clean the clutch cover gasket mating surfaces than anything else. I also cleaned what oily deposits I could from inside the engine casings. It's now back together with clean oil so I'll see how that goes. I've moved away from Spectro oil and will decide what to use in the future based on the information above. Thanks everyone for their input, and here's what it looks like now.