Yup, he had same issue.
All plug were also foul SOLID. After plug and O2 change, took 100Km before it start to run properly,
We change oil also. didn't like the smell. change it again at 500Km, to clean it up. From what I read, valve train is exotic, but reliable if running with good oil.

He paid less than 1000$, 2 years ago.
But I as said, it wasn't looking good. It was dirty, bad tire, brake were rusted out, engine running rough. He took a chance...