You need to use a 2cycle oil intended for air cooled motors. The air cooled motors operate a higher running temperature and TWC3 is not intended for air cooled motors. Your motor has an impeller, but it is used to cool the base of the motor as well as the exhaust leg. By doing this it prevents the radiating heat from over heating the power head.
16:1 ratio is an excellent fuel to oil ratio for your motor. Improved lubrication will provide longevity to your motor and keep its owner happy!!
Stihl makes a good Two cycle air cooled oil.
Your motor looks and sounds great!! Cool present!!
Cheers,
Cajuncook1
