It's an old air cooled , iron liner engine, not a modern water cooled plated cylinder engine, so its up to you if you want to go as lean as 80/1, 100/1 ( which is fine in modern engines, but maybe a risk in older engines ?)
Short term it will probably run okay on just about any oil, at any ratio that has been mentioned, but good oil mixed at a sensible ratio should give the best long term life for engine wear.
I once accidentally mixed up fork oil with my petrol ( picked up the wrong silkolene bottle) and rode a trial with no problems before I realised , But I don't recommend it !
ty175 id
in Yamaha
Posted
https://www.ty175.co.uk/date-your-ty175/