Menu . Apr 19, 2010. Motorcycle Backfire: What Causes a Motorcycle To Backfire? A few reasons your exhaust could be backfiring: Another possible reason for your backfire is a spark plug refusing to âsparkâ when the exhaust valve opens. Times Square While an engine backfire (or âafterfireâ, ... Why does my motorcycle backfire on deceleration? Page 1 of 2 1 2 Next > mrpackerguy Member. Up to 20 people were injured in the mad rush, reports NBC New York. Step 1: Replace the Muffler. Carburetor Backfire a Popping Sound Several loud bangs sounded in the Big Apple on Tuesday night ⦠Call your County and State legislators. Coolest Motorcycle Helmets; Best Full Face ⦠The Symptom: Engine hesitates, and a popping sound comes from the engine. Page 1 of 2 1 2 Next > mrpackerguy Member. 1 of 2 Go to page. A motorcycle running rich is sometimes viewed as the opposite as a motorcycle running lean. Preventing Backfire on Motorcycle Exhausts | DoItYourself.com This led to people pushing the metal fences, which led to gunshot-like sounds, which led to mass chaos and the queen and her gang to return inside the palace.