Positive Crankcase Ventilation: Service and Repair

Every 30,000 miles, replace PCV valve and clean crankcase inlet air cleaner. If vehicle is used extensively for short trips with frequent idling, this service may have to be performed sooner.
To clean the passage in the carburetor, remove carburetor from engine. Turn a 1/4 inch drill bit by hand through the passage to dislodge the solid particles, then blow clean using compressed air. If necessary, use a smaller drill bit so that no metal will be removed.