The Importance of Frequent Valve Adjustment

Many air-cooled VW owners don't adjust their engine valves as often as they should. Valves stems stretch and become longer slowly over time — exhaust valves in particular. Eventually, this stretching results in valves that are too tight and lack adequate lash clearance. Without clearance, valves become too loose in the valve seat, resulting in hot gases leaking past the valve, causing the valve to overheat. It takes very little time for an overheated valve to weaken, burn, and ultimately break.

Even if only minimal adjustment is needed each time, frequent valve adjustment also gives the opportunity to catch a failing exhaust valve before it breaks. Exhaust valves are among the hardest-working components of the air-cooled Volkswagen engine. Over the course of time and incremental adjustments, the valve will eventually weaken and begin to stretch abnormally. If the valve adjustment nut requires anything more than ⅛ turn, the valve is failing; the time to replace the valve has arrived. A broken valve can be disastrous for the engine.