Here is a picture of the MT-DAIL indicator in the # 1 Cylinder at TDC (Top Dead Center) then notice the timing tape on the PTO and we drew a simple line on the engine bracket to line up with the tape at TDC. Once you have the line and the tape all lined up at TDC remove the indicator and check the timing before you start the job. It should be around 22 degrees BTDC. Once the MT-IGN/REV is installed you will need to check the timing again and make any adjustments with the initial timing correction needed to bring the timing back close to the stock timing mark.