1. Remove the distributor cover with high voltage wires. Loosen the bolts and remove the valve cover, being careful not to damage the gasket.
2. The engine can be turned by either jacking up one of the front wheels and turning it in 4th or 5th gear, or with a wrench thrown over the crankshaft pulley bolt. The engine will be easier to crank if you first remove the spark plugs.
3. Prepare paper and pencil in order to write down the measured valve clearances.
4. Turn the engine so that the camshaft cam closest to the pulley points vertically upwards. Using feeler gauges, measure the gap between the cam base and the tappet (see photo) and write down the resulting value.
5. Repeat measurements for the remaining 7 valves, turning the engine as necessary so that the desired cam points vertically upwards.
6. Calculate the difference between the results obtained and the required valve clearance (see specs). Note that intake valves have a different valve clearance than exhaust valves. Counting from either end of the engine, the valves are arranged in the following sequence: Exhaust - Inlet - Inlet - Exhaust - Exhaust - Inlet - Inlet - Exhaust.
7. If any of the measured clearances is out of specification, it must be adjusted as indicated below.
8. If all measured clearances are within the specified limits, reinstall the valve cover with a new gasket (if it is needed). Please note that under the bolt on the side of the timing belt there is a copper washer (see photo).