DLE120 Admission valve

This is the admission valve for the DLE 120 twin, a large two-stroke petrol engine for big scale models.

The part itself is the admission (reed) valve, which admits the fuel charge into the crankcase and closes to trap it.

Why it is replaced: reed petals lose their spring with age and fail to seal, so the engine idles badly and loses bottom-end power.

Fitting note: Hold the valve up to the light to check it seats, and renew rather than bend a tired petal.