1 - control valve
2 - steel mesh
3 - filter
Thanks to this system, gases from the crankcase are sucked back through the intake pipe and the air filter. The system has a valve (1) (see illustration above), to return gases from the crankcase back to the intake manifold. The air required for ventilation is sucked in through the carburetor air filter and through a hose connected between the air filter and the cylinder head cover in the upper part of the cylinder head and is fed from there to the crankcase.
At full load, the vacuum in the intake manifold is sufficient to suck gases through the valve and hose in the opposite direction.
To ensure that the ventilation system works properly, the following work must be carried out every 20,000 km.
1. Run the engine to idle and disconnect the hose from the valve. If the valve is working correctly, air noise will be heard as air flows through. If you put your finger on the valve opening, you can feel the vacuum.
2. At this point, shut off and blow out all hoses with compressed air. Clogged hoses must always be replaced.