How do you adjust tappets on a 3 cylinder engine?

To adjust tappets on a 3-cylinder engine, first ensure the engine is cool and remove any necessary components to access the valve cover. Rotate the crankshaft to align the timing marks, then check the clearance of each tappet using a feeler gauge. Adjust the tappet screws or shims as needed to achieve the manufacturer's specified clearance, ensuring to tighten lock nuts after adjustments. Repeat this process for all cylinders, following the firing order to maintain proper timing.