On the first type 1 engines and on all type 3 engines, the crankcase pressure is not only discharged through the air filter but also through a tube mounted at the oil filler inlet and discharged under the engine. With the latest type 1 engines, this has been overhauled and this tube has not been used anymore.
This tube runs on type 1 engines through the engine sheet metal, at this point the hose is provided with a rubber as protection, but even more important is that it is well sealed through this rubber so that no hot air is sucked under the engine, this to ensure good cooling of the engine.
On type 1 and type 3 motors, the end of this tube is equipped with an end rubber with a small opening. This opening is intended to relieve the pressure from the crankcase and to prevent dirt from being sucked in. Clean this rubber regularly to prevent it from becoming dirty and replace it if it is torn.
The protective/sealing rubber is ready for immediate installation. Due to the manufacturing process, the lower part of the rubber is not yet open in most cases. Open the seam by making a notch with a knife.
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