Spark Exhaust dB Killer Round Old Style 32 mm 18° Open Universal G9912

The eighteen-degree insert for Spark's older round cases. If your silencer predates the current families and takes a slanted plug rather than a straight one, this is the part number.

Key Features

• dB killer for Spark round silencers, older generation.
• Ø 47 mm outer, 32 mm internal bore.
• 18° seat angle.
• Open type — no perforated section.
• Stainless steel, removable.
• Spark part number G9912, made in Mantova, Italy.

Why an Angle

Not every silencer outlet is cut square. Where the end cap sits at a slant, the insert has to sit at the same slant or it will not seat — and an insert that does not seat rattles, works loose and eventually leaves the motorcycle at speed.

Eighteen degrees is the figure for this generation of round cases. Spark also builds a 16° version for the GP Style and a 34° version for the newer round and Megaphone cases; the numbers are not interchangeable and the difference is not something you can eyeball.

Old Style, Still Supported

Spark keeps this article in the current price list for silencers it no longer builds. That is worth noting: an exhaust bought fifteen years ago can still be brought back to a usable noise level with a part that costs less than an hour of workshop time.

If you are not sure which generation your silencer belongs to, measure the outlet bore and the seat angle and send us both.

Thirty-Two Millimetres

The bore is the number that decides how much the insert actually does. Thirty-two through a forty-seven millimetre case is a substantial narrowing, and on a large-capacity single or twin it is audible immediately.

Approval

None, and none conferred. This is a noise-management part for track and paddock use. A silencer without a certificate does not gain one because an insert has been fitted, whatever the reduction measures.

Stainless, Because It Comes Out Again

An insert lives in the hottest, dirtiest part of the exhaust and gets pulled out and pushed back in repeatedly. Stainless tolerates that: it does not gall against the case wall and it does not seize into a silencer that has been left standing over a winter.

Ordering

One insert per silencer. On a twin-can installation with two round cases you need two, and they are the same article — unlike the angled Moto GP cases, this one has no left or right.