Oil Metering Pump Failure
Symptoms
The apex seals lose their lubrication source. Wear accelerates dramatically, and the engine may seize if run for extended periods without lubrication.
Cause
The mechanical oil metering pump (OMP) injects two-stroke oil into the combustion chambers. After 50 years, the pump's internal seals deteriorate, the delivery lines crack or clog, and the pump may lose prime. Some owners have disconnected the pump and switched to premix, this works but requires religious discipline with oil-to-fuel ratios.
Fix
Inspect the OMP and its delivery lines at every service.
Replace cracked or hardened silicone delivery lines.
If the pump is not salvageable, commit to premix at 1:200 ratio.
If premixing, label the fuel filler cap and document the procedure so future owners (or anyone who borrows the car) cannot accidentally run the engine without oil.
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