I have the EXACT same problem except for running/smoking issues. Just have a bunch of oil dripping out the crack at the bottom of the fairing. I see oil on the lower chamber and coming down from above too. On the front cylinder it appears to be coming from the exhaust port.

This bike has no oil pump (using HRC plugs in the engine) and I mixed it around 40 or 44:1 with Castor oil (can't remember the exact name but the previous owner used it so I bought the same thing). He told me to run 50:1 but I was concerned that wasn't enough oil. It smoked a lot more when I put my first tank of premix in it so maybe I have a combination of too much oil and leaking exhausts.

What parts are needed to seal the exhausts and where can they be sourced?

Thanks guys.