Spark Exhaust dB Killer Round and Oval Old Style 30 mm 18 Holes G9902

Eighteen holes and a thirty millimetre bore — the narrowest insert in Spark's round-case range, for the round and oval silencers of the old style.

Key Features

• dB killer for Spark round and oval silencers, old style.
• Ø 47.3 mm outer, 30 mm internal bore.
• Perforated: 18 holes.
• Stainless steel, removable with hand tools.
• Confers no approval on the silencer it is fitted to.
• Spark part number G9902, made in Mantova, Italy.

The Narrowest Bore Spark Lists

Thirty millimetres, against thirty-two for most of the round-case inserts and thirty-five or forty for the modern families. Two millimetres does not sound like much until you work out the area: a 30 mm bore passes roughly twelve per cent less than a 32.

That is the article's purpose. It is for the case where the usual insert is not enough — an older, larger-bore silencer, or a venue with a limit set low.

Eighteen Holes

Fewer than the twenty-eight of the newer round insert, and a different acoustic result. A smaller number of holes over the same length means each one carries more gas, which shifts the frequency the insert attenuates most.

Spark did not choose the number for looks. It was matched to the internal volume of the cases it goes into.

Round and Oval, Old Style

Two case profiles, one insert. Spark's earlier generation used a common outlet section across both the round and the oval silencer, so a single article number covers them. The current families do not share that section, which is why there are now several inserts instead of one.

Keeping an Old Exhaust Usable

The reason a part like this stays in a 2026 price list is that Spark exhausts outlive the motorcycles they were bought for. A silencer from an earlier decade that has lost its insert is not scrap; it is a silencer waiting for a forty-one euro part.

If you are matching one to a case you already own, measure the outlet bore and count the seat angle before ordering. We will check the number against Spark's list.

Track Use

This insert exists for noise limits, not for paperwork. Spark's old-style round and oval cases were sold without homologation and remain without it; fitting the plug lowers the reading and changes nothing else.