ASK THE MXPERTS: WHAT DOES THE WIRE SCREEN INSIDE MY KTM 450SXF MUFFLER DO?

This wire screen is not a USFS-approved spark arrestor.

ON RE-ENTRY

Dear MXA,

I never noticed that there was a wire screen inside the muffler on my KTM 350SXF until I looked into it with a flashlight and saw it. Is this a spark arrestor? Does it hurt power? Can I remove it?

KTMs have come with wire screens inside the mufflers for years. Sometimes they are near the end of the muffler, and sometimes they are farther in. They don’t help the power and are really there just to make a minor improvement in sound-deadening. They are not spark arrestors and are not USFS-approved. In the past, KTM used a thin-gauge wire, and it would burn up by itself in a matter of hours. Over the last two years, KTM has increased the gauge of the wire, and it is now more resistant to burning up. Our quick and-dirty fix? We take a long pointy object, like a screwdriver, and poke holes in the wire screen. With the wire fragmented, it will burn out of the muffler in its own good time.

The 2019 Husky FC350 and FC450 comes with a rolled-up cone-sahped section of perf core, which not only makes the engine quieter, but hurts horsepower.