Depends what it is but it seems a common issue with this engines at certain mileage and history, my old lump burnt oil esp after a shoddy VXL warranty job if I kept in the lower rev range it would still use some and anything over 5k used to cover the road and consume more.
Clogged / worn rings, maybe but if you go for a overhaul then chains and stem valve guides and seals would be done 🙁