You may not believe this but in most old jap bikes if you unplug the ignition switch it should fire up, the switch was just a contact to ground when 'off'.
Don’t forget to wire in a kill switch if otherwise not fitted.
With the gas cap find a sacrificial screwdriver & drive it in. Twist (perhaps with some leverage). This should work 9/10 times.
If you take either of these mechanisms apart you can disable the keying bits.
This is making me sound a little dubious, having had my first bike (PE175T as it happens) stolen I subscribe to the theory of capital punishment for bike thieves.
To those who perhaps feel that I have just posted info on how to steal bikes, this is only news to honest people, crims have already tried all this out.
Yes the oil mix is injected std. You will find the container under the seat if it is still there & the line leads down to the oil pump which is operated by the throttle cable (splits into 2). Drain all the old oil & undo the bleed screw on the pump until new oil starts to flow through.