Both the above cameras are battery driven, the battery holders being clean and good. However the motors will not work and I wonder whether anybody has experience of these and any pointers how to get them going. The Yashica was purchased as it offers auto-threading to the take up spool, unusual in Standard 8mm. Part of its electric circuit works as the electric zoom operates.
Welcome Grahame. We need more movie camera people around here.
I have a few non working ones also but have not tried fixing them yet. My guess is the grease dried or hardened enough that the motor can't turn the gears or the wires need resoldering. Of course, it could also be a "frozen" motor. Those are the most likely causes.