Muffler for QJMotor SRK 400: Racing Spec
This muffler is built for the QJMotor SRK 400 and supplied to a written specification, so the part that comes off the line in the next order matches the one you approved. Fitment, base material and finish are fixed before sampling starts — that is what keeps the racing spec programme stable once it moves from first order to repeat order.
Most buyers come to us after something went wrong: packing that arrived crushed at the port, or warranty claims traced back to a single lot. Both are avoidable when the specification is written down before bulk and the approved sample is kept as the reference.

Specification
| Part | Muffler |
|---|---|
| Fitment | QJMotor SRK 400 |
| Version | Racing Spec |
| Base material | Semi-Metallic Compound |
| Typical use | Adventure Travel |
| MOQ | 500 pieces per specification |
| Sampling | 14 working days, 5 days per revision |
| Bulk lead time | 25-35 days after approval |
| Compliance | ISO/TS 16949 |
What decides whether it lasts
- Material — Semi-Metallic Compound is the base; treat any substitution as a new approval.
- Hardness and heat treatment — recorded per lot, not per batch of paperwork.
- Fitment tolerance — checked on the actual QJMotor SRK 400 mounting, not on a catalogue drawing.
- Finish — powder coating holds up where the machine sees salt, mud and daily washing.
- Packing — individual packing plus inner cartons sized for the workshop bench.

Processes used on this line
- sintering
- CNC machining
- ultrasonic cleaning
- injection moulding
- robot welding
- electroplating
Fitment notes
Confirm the fitment against the VIN or the frame number before ordering; two model years often share a name and not a part.
Where it is used
The racing spec build is the one most often ordered for adventure travel. Riders also fit it for food delivery, rental fleets, track days, adventure travel.
Ordering
- Confirm the model year and frame number before ordering.
- Approve a sample made from the actual bulk material.
- Fix the packing and marking at quotation stage.
- Book inspection before the balance payment, not after it.
Questions buyers ask
How is packing specified?
Individual packing, inner box quantity and carton marking are confirmed at quotation stage so the cartons arrive ready for your warehouse.
Do you handle mixed containers?
Yes. Most programmes consolidate several part numbers into one container to keep freight sensible at 500 pieces per line.
What happens if a lot fails inspection?
The lot is re-inspected against the golden sample, and replacement pieces ship on the next available booking at our cost.
How long does sampling take?
Samples leave the factory in 14 working days, and each revision round adds about 5 days once you have seen the first piece.
Share a sample or a drawing and we will quote against a written specification, not against a photograph.







