A rattle or buzz from the exhaust area at certain revs is usually a loose heat shield screw, a broken shield clip, a loose silencer mount or a perished rubber bush. It can also be a broken baffle inside the silencer, or a nearby part that touches the pipe: the centre stand, the brake pedal, a footpeg bracket or a chain guard. Vibration grows with looseness, so a small rattle can end with a part falling off.
Is it safe to ride?
Yes with care. Stop if a heat shield or the silencer is hanging or touching the tyre, chain or your leg.
Quick checks first
- Engine cold: tap each heat shield. Does it buzz?
- Shake the silencer by hand. Does it move at the mount?
- Is the centre stand tucked up and its spring holding it?
- Look for shiny rub marks on the pipe or the parts near it.
Diagnose it step by step
1Does the rattle happen with the bike on the stand and the engine revved in neutral?
- Yes: go to step 2.
- No, only over bumps: check the centre stand, side stand and chain guard. See Centre stand is hard to use or scrapes and Find and fix rattles.
2Engine cold: press each heat shield with your hand and rev the engine (helper, outside). Does the rattle stop when you press a shield?
- Yes: tighten or replace its screws and clips with Check exhaust mounts and heat shields.
- No: go to step 3.
3Does the silencer move at the rear mount or the joint with the header?
- Yes: tighten the mount and replace worn rubber bushes with the same repair. If the joint puffs, go to Find and fix an exhaust leak.
- No: go to step 4.
4Shake and tap the cold silencer. Is there a loose piece inside?
- Yes: a broken baffle. Replace the silencer. See Exhaust has become much louder.
- No: go to step 5.
5Is the whole engine moving more than usual?
- Yes: check Check engine mounting bolts. A loose engine shakes the exhaust.
- No: the rattle may be elsewhere. Go to Rattling from panels, mudguards or the seat.
Causes, most likely first
| Cause | How to confirm | Fix |
|---|---|---|
| Loose heat shield screw or clip | Rattle stops when pressed | Check exhaust mounts and heat shields |
| Loose silencer mount or worn bush | Silencer moves | Check exhaust mounts and heat shields |
| Stand or bracket touching the pipe | Rub marks, rattle over bumps | Find and fix rattles |
| Broken internal baffle | Loose piece inside | Replace the silencer |
| Loose engine mounts | Engine moves | Check engine mounting bolts |
Reference values (K-Light 125)
| Item | Value | PDF page |
|---|---|---|
| Muffler mounting bolt | 22 to 29 N·m | 106 |



