This section briefly discusses the peculiarities of the Lafranconi muffler for SS 125 - SST 125. On the side of the muffler is stamped with Cagiva Lafranconi DGM 30229S (formerly as Harley Davidson Lafranconi DGM 30229S). The number 30229S indicates the approval granted by Direzione Generale della Motorizzazione in Italy. With this theme you can find different mufflers produced by Lafranconi to fit the structure of other motorcycles.
The muffler is formed by a chromium-plated metal casing with the two halves are welded together and a tubular manifold 3 hooks. Inside the muffler it is placed the exhaust system, consisting of 4 separate pieces, embedded between them. The pieces are welded on one half of the muffler. The 4 pieces are constituted by:
an expansion cone
b) a silencer pot
c) a diaphragm
d) a spark arrestor
The images below show a sectioned muffler. It's possible to see the placement of the various internal components, the weak point of this muffler is made from the pot silencer whose holes are subject to accumulate deposits that diminish the diameter of the holes themselves. The muffler is not openable. The only removable piece is the spark arrestor. The muffler can be cleaned using caustic soda. Cleaning with caustic soda it is described in the "restoration" section of this site, which should be consulted.
Pictures: (1) a sectioned muffler; (2) the first stage; (3) the second stage; (4) silencer pot; (5) silencer pot and diaphragm; (6) set of 4 components; (7) expansion cone with 12 holes; (8) lateral view of silencer pot; (9) silencer pot; (10) the silencer consists in two circular-section rings, with 12 holes each, the two rings are connected toghether with 4 pipes.
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Below: layout of Lafranconi muffler DGM 30229S (in italian).