G'day tubes,
Are you referring to the 125cc Model 5 Victa 18 you pictured in this thread? https://www.outdoorking-forum.com.au/forum/u.../identifying-model-number.html#Post87496

If so, that is a 2-stroke engine [as per the heading of this forum section], and runs a 'petroil' fuel mix, not an oil sump [4-strokes have those].
Don't try to run it on straight petrol!

The correct mix for these is 1 part 2-stroke oil to 25 parts petrol, by volume. E.g for each litre of petrol, add 40 mL of oil - mix this in the fuel can.
Be sure to use only non-ethanol petrol, even if you have to go to 95 Premium grade to get it.

Cheers,
Gadge

"ODK Mods can explain it to you, but they can't understand it for you..."

"Crazy can be medicated, ignorance can be educated - but there is no cure for stupid..."