Four-Stroke Engine Specification Example for Assembly Programmes: Waterproof Version
Four-Stroke Engine Specification Example for Assembly Programmes: Waterproof Version
This is a worked specification for four-stroke engine in a waterproof version programme. It is the document we would send a buyer who asks what exactly they are getting: the material, the dimensions that are actually controlled, the finish, and the checks that happen before anything is packed.
The waterproof version version exists because the duty cycle on assembly programmes is not the same as on a showroom vehicle. Where the two are specified identically, something fails later — usually premature wear on the first batch.

Example specification
| Item | Four-Stroke Engine |
|---|---|
| Application | Assembly Programmes |
| Version | Waterproof Version |
| Base material | Zinc Plated Steel |
| Controlled dimensions | 5 key dimensions, recorded per lot |
| Tolerance band | ±0.1 mm |
| Finish | powder coated |
| MOQ | 200 pieces per specification |
| Sampling | 7 working days, 5 days per revision |
| Compliance | RoHS |
How the example is built up
- Start from the duty cycle, not from the catalogue photograph.
- Fix the base material in writing — Zinc Plated Steel, in this example.
- List the dimensions that are actually controlled and the tolerance on each.
- Name the finish and what it has to survive.
- State the inspection level and who pays when a lot fails.

Processes involved
- anodising
- sintering
- precision stamping
- powder coating
- ultrasonic cleaning
- assembly line testing
Where this example applies
Programmes that run waterproof version most often specify this build for assembly programmes. Related applications include boat trailers, construction equipment, municipal fleets, rental motorcycles, utility trailers.
Checks before packing
- Dimensional report against the approved drawing.
- AQL 2.5 sampling on the finished lot.
- Finish inspection under agreed lighting.
- Carton drop test on the first lot of a new packing specification.
Questions buyers ask
Do you handle mixed containers?
Yes. Most programmes consolidate several part numbers into one container to keep freight sensible at 200 pieces per line.
Can you match an existing sample?
Send a sample and we will reverse-engineer the specification, then produce a counter sample for approval before any bulk starts.
What testing is included?
Standard lots ship with dimensional and hardness reports. RoHS documentation is issued with the shipment when your market requires it.
Can the specification be held on file?
Yes. Once approved, the specification is recorded against your part number so a reorder reproduces the RoHS-compliant build instead of a fresh interpretation.
Tell us the model, the fitment and the quantity and we will hold a production slot for you.



