S40 backfiring

[Wordherder]

We have a nearly-new 2006 Suzuki S40 that backfires when you start slowing down -- unless you grab the clutch, as soon as the engine braking kicks in, you get a single bang that sounds like a shotgun. I mean, loud.

I don't have a lot of experience with one-cyl. bikes, but I can't imagine that's normal.

It's almost time for its 600-mile service - what should I ask the mechanics to check? Valves?

Thanks!

[niterider]

Have the mechanic drive it and figure out what is wrong with it and have him fix it. Let them diagnose the problem. My bike does the same thing, but I added loud pipes and did not redo the carbs.