Spark Exhaust dB Killer Grid-O 38 mm Open 150 mm Universal G9982

A hundred and fifty millimetres of Grid-O insert at a thirty-eight millimetre bore. Spark names four Yamaha exhausts against it, which tells you where most of them go.

Key Features

• dB killer for Spark Grid-O silencers.
• Ø 51.5 mm outer, 38 mm internal bore, 150 mm long.
• Open type, no perforation.
• Listed by Spark for exhausts GYA8862, GYA8870, GYA8874 and GYA8876.
• Stainless steel, removable.
• Spark part number G9982, made in Mantova, Italy.

The Long Grid-O Insert

At 150 mm this is the longest of the four Grid-O plugs, and length is where an open insert gets its effect. A short plug narrows the exit at a point; a long one works on the gas column over a distance and takes more out for the same bore.

It also needs the room. Confirm that the case has 150 mm of clear section behind the outlet before ordering.

Four Yamaha Exhausts

GYA8862, GYA8870, GYA8874 and GYA8876 — Spark's MT-07 and XSR700 family systems. On those the insert is a spare part rather than an accessory: it came with the exhaust and this is how you replace it.

On any other Grid-O case with a 38 mm outlet it is an option rather than a spare.

Thirty-Eight Millimetres

The middle of the Grid-O range. Wider than the 32 and narrower than the 40 and the 45, which puts it in the sensible place for a mid-capacity twin — enough restriction to matter, not enough to hurt the mid-range.

Grid-O and Its Mesh

The Grid-O case ends in a woven titanium grid across the entire outlet. That mesh is structural and acoustic at once, and it is the reason all four inserts for this family are open: adding perforation behind a mesh buys little and costs flow.

Order It With the Exhaust

If you are buying one of the four Yamaha systems Spark names, the insert is already in the box. If you are buying a used one, it very often is not — ask the seller before you assume, because a system without its plug is a system you cannot take to most circuits.

Approval

On a homologated exhaust the supplied insert is part of the certified configuration and belongs in the silencer. On a racing article no insert creates an approval.