Ive run both a teccy and a briggs with no oil- the briggs was by accident tho- i ran it like 5 mins with no oil , after 3 days of loading the combustion chamber with PB blaster it freed up enough to run normal again.
The teccy was on a push mower- place i bot years ago the owner left it- i spent some time cleaning it, a full tune up, oil change, blade sharpening , added a fuel filter. The thing ran before i did all that, once i changed everything do you think it would start? I tried for a whole damn hour to start it- so i dumped the new oil out re added the old crappy oil , put the old plug in , took the filter out- and thing started right up- i ran it off and on for like 3 years like that- never checked the oil or nothin.
I let it go with the house- it was starting to knock a lil louder - i was hoping to blow it up tho.