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TKART magazine Expert Advice | Intake silencer: 7 tricks and cunning measures by professionals
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Mattia Livraghi
26 March 2023 • 8 min. read
“In addition to regular cleaning, intake silencers require a thorough and complete overhaul in order to fulfil their duties and prevent numerous problems”
“When the filter is clean, the engine can express its full potential and the carburetion can be adjusted without being affected by the impact of external bodies”.

If you had ever thought that the topic related to the maintenance of suction filters ended with the article "Advice from the experts | How to clean the intake silencer by real karting professionals!", you'll have to change your mind. Such an important component requires precautions that go far beyond mere cleaning. In fact, to summarise, the silencer performs a vital function in karts equipped with 2-stroke engines, protecting the engine thanks to its filtering properties and reducing noise pollution. In addition, this element has a significant impact on engine performance, affecting the air flow towards the carburettor and consequently the carburetion. Therefore, although it may seem trivial, a kart driver must be able to exploit those small details that make a big difference both in terms of the performance and reliability of filters. What are these measures and how are they implemented? We explain it to you here, again with the qualified advice of Massimo Aceto. The owner of the ACE Racing team, as well as a professional mechanic in international kart competitions, reveals the tricks related to the complete management of intake silencers.

Video. To learn and apply the tricks of the trade useful for overhauling a filter flawlessly, you must first open the component and break it down into its elements. A FreeLine brand intake silencer was used for the preparation of this article, model B23R, diameter of the intake ducts 23 mm, suitable for direct-drive engines.
Most of the measures indicated in this article can also be extended to intake silencers of other brands with a cartridge filter element (instead of the sponge one), except where indicated.

FreeLine produces this type of oil, which can be found online on the major e-commerce platforms specialised in karting items.

1 Oil to increase the filtering action of the sponge

Adhesive oil should be applied after complete cleaning of the intake silencer. Once drying is complete, an additional touch of prevention can be given, applying a specific oil to the sponge that creates a further protective "surface" so as to prevent impurities from penetrating the filter element. This solution was invented for motocross, where the filters are exposed to a greater quantity of earth, sand and dust, but it is also adopted on the track. Although there are specific products such as, for example, the special FreeLine liquid (read"Must Have | 8 products for cleaning the intake silencer for karts" to find out which are the main tools to use in managing filters, editor's note), in karting the same practice is less widespread, because it generates a slight negative impact on engine performance. In fact, the oil makes carburation rich (decreasing the air supply and consequently increasing the petrol flow) and slightly "throttles" the engine. The sponge retains its filtering capacity even if no oil is applied to it, but the adhesive oil expands the potential of the filter element because it allows it to hold more dust and generally more impurities. Therefore it is recommended on circuits often hit by gusts of wind that bring dust and sand onto the track. On the other hand, adhesive oil is not to be used with cartridge filters: it is only suitable for those with a sponge filter.

2 The venturi duct of the carburettor reveals whether the cleaning of the intake silencer has been carried out correctly

Assessing the effectiveness of cleaning is simple because the answer is visible when the silencer is dismanteled to service it (follow the instructions given in
"Doctor TKART - Servicing intake silencers" to do it properly, editor's note) or for any check on the engine. In fact, the inlet to the carburettor mouth, properly known as the venturi duct, is only clean if the intake silencer has been cleaned correctly. If, on the other hand, dirt residues remain in the filter, they will tend to be sucked in by the engine and therefore "stain" the carburetor inlet port. A dirty venturi will have a series of deposits, which can be caused by rubber fragments or other impurities. It should be noted that to understand if a silencer has been cleaned well it is essential to reassemble all its components in the same position and pay particular attention to the filter element, whether it is a sponge or cartridge type.

In addition to the classic rubber fragments, it should be noted that other dirt residues (for example blades of grass) can "stain" the carburetor inlet port, risking being sucked into the engine.
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