This is how I check the gears on a gear case I bought on ebay for grinding and proper function of the gears before splitting the case if necessary. This engine will be going in a 1978 rear mono shock yz80.
This is an air cooled 80. The cases are different because of the liquid cooling and power valve. It will wind up pretty fast and with the 2 stroke improvements I do, (gear for gear) it will stay along side the newer ones.
