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AMAL / Arreche 17mm carburetor explained: how it works, where it fits, and how to tune it for your Puch
The AMAL / Arreche 17mm carburetor is a compact slide carburetor for Puch riders who want a classic, simple tuning option with more airflow than many original small carburetors.
This guide explains what the 17mm AMAL / Arreche is, why the AMAL and Arreche names appear together, how the carburetor circuits work, and how to approach tuning safely on a Puch moped.
Why talk about AMAL and Arreche together?
AMAL is a British carburettor name with deep roots in the motorcycle world. AMAL carburettors were used across the British motorcycle industry for decades, and the name is strongly connected with classic slide carburetors such as the Monobloc and Concentric.
For Puch moped parts, the name usually appears as AMAL / Arreche. That matters because Arreche obtained a license in Spain to produce and sell AMAL carburetors, and Arreche carburetors were produced and sold for more than 50 years.
| Name / term | What it means for this article |
|---|---|
| AMAL | The historic British carburettor name and design heritage behind many classic slide carburetors. |
| Arreche | The Spanish manufacturer connected with licensed AMAL-style carburetor production and moped/scooter carburetors. |
| 217/24 | The product reference seen with the 17mm AMAL / Arreche moped carburetor. |
| 17mm | The carburetor bore size. On a Puch, this sits between small original-style carbs and larger tuning carbs. |
What is the AMAL / Arreche 17mm carburetor for Puch?
The version we sell at Puchshop is the AMAL / Arreche 217/24 - 17mm carburetor with cable choke. The 17mm AMAL / Arreche 217/24 has a 24mm manifold connection with the bushing installed, 25mm without the bushing, and a 27mm air-filter connection.
In practical Puch terms, that makes it a compact tuning carburetor for riders who want more airflow than many original 12mm, 14mm, or 15mm setups, while still keeping a simple slide-carburetor layout. It is not as complex or as adjustable as a Dellorto PHBG, and it is not the same style of carburetor as a flat-slide Mikuni TM or PWK-style racing carb.
AMAL / Arreche 17mm carburetor with cable choke for Puch moped tuning.
| Feature | Practical meaning | Shop |
|---|---|---|
| 17mm bore | A useful step for mild Puch tuning, especially where a standard carburetor feels restrictive. | View carburetor |
| Cable choke | Cold-start enrichment is controlled by a cable-operated choke/enrichment system. | View AMAL parts |
| 24mm manifold connection | Check your intake manifold size before ordering or installing. | View manifolds |
| 27mm air-filter connection | Use an air filter that fits correctly and does not restrict or leak. | View air filters |
| Simple slide layout | Easy to understand, clean, and tune, but it still needs correct jetting. | View jets |
Need the AMAL / Arreche 17mm carburetor?
Check the Puchshop product page before ordering and confirm your manifold, air filter, throttle cable, and jetting parts match your setup.
View the AMAL / Arreche 17mm carburetor Always tune from a safe rich baseline after installation.How does this AMAL slide carburetor work?
A slide carburetor controls air with the throttle slide. As you open the throttle, the slide lifts, the engine can breathe more air, and fuel is pulled through different fuel pathways inside the carburetor. In carburetor language, those pathways are often called circuits.
A circuit, in carburetor terms, means a fuel/air pathway in the carburetor that mainly works during a certain throttle range. On a simple needle-type carburetor, the main areas are the pilot or idle circuit, the throttle slide cutaway area, the needle and needle jet, and the main jet.
These areas overlap. A moped does not suddenly switch from one circuit to another like a light switch. When you tune, you are smoothing the transitions so the engine starts, idles, pulls away, accelerates, and runs at full throttle without bogging, four-stroking, overheating, or leaning out.
| Throttle position | Main influence | What it controls |
|---|---|---|
| Closed to 1/8 | Pilot / idle circuit | Starting, idle quality, warm low-speed running, and the first response when you open the throttle. |
| 1/8 to 1/4 | Throttle slide cutaway / transition | How cleanly the engine pulls away from low throttle without coughing, bogging, or hanging lean. |
| 1/4 to 3/4 | Needle and needle jet | Mid-throttle acceleration, cruising feel, and how the engine transitions toward high throttle. |
| 3/4 to full | Main jet | High-throttle fuel supply, full-load safety, top-end power, and engine temperature. |
| Cold start only | Choke / enrichment | Extra fuel for cold starting and warm-up. It should be fully closed once the engine is warm. |
Interactive AMAL tuning simulator
Use the slider below to see which AMAL / Arreche carburetor parts have the strongest influence as the throttle opens. This is a simplified learning tool, not a replacement for real test riding, plug checks, temperature checks and safe jetting.
Interactive AMAL / Arreche tuning simulator
Twist the throttle below to see how the AMAL / Arreche pilot circuit, throttle slide cutaway, needle and needle jet, and main jet hand off fuel-metering responsibility as throttle opening and engine load increase.
Active AMAL / Arreche components
- Pilot / Idle CircuitEstimated influence: 100%Controls idle, starting behavior and very small throttle openings. Check this area when the engine starts badly, will not idle, hangs on idle or reacts poorly just off closed throttle.
Constant systems
Tuning order for a safe AMAL / Arreche baseline
Before changing jets, make sure the basics are correct. A carburetor cannot tune around false air, poor ignition, weak fuel flow, a blocked tank vent, a leaking exhaust, or a throttle cable that does not let the throttle slide close fully.
Common AMAL / Arreche symptoms and where to look first
Most carburetor problems become easier to understand when you connect the symptom to the throttle position where it happens. Use the table below as a starting point before changing parts.
| Symptom | Most likely area to inspect first | Workshop note |
|---|---|---|
| Hard cold start | Choke/enrichment, pilot circuit, fuel flow | Make sure the choke works and the idle circuit is clean. |
| Won’t idle | Idle screw, pilot circuit, air leak, throttle slide height | Set idle only after the engine is warm and mechanically healthy. |
| Bogs when throttle opens | Pilot-to-needle transition, throttle slide cutaway, needle clip | Use the simulator above to focus on the early throttle-opening range. |
| Four-strokes or sputters at wide-open throttle | Main jet too rich | Step down carefully and retest under load. |
| Runs hot or loses power at high rpm | Main jet too lean, fuel starvation, false air | Stop testing until the cause is found. |
| Fuel leaks or overflows | Float, float needle, dirt in the seat | Clean the float bowl and inspect the needle tip. |
Where does the 17mm AMAL / Arreche fit compared with other Puch carburetors?
The 17mm AMAL / Arreche sits in a useful middle ground. It is more of a classic moped tuning carburetor than a modern race carburetor. For a mild 50cc or modest 70cc Puch setup, it can be a clean and simple choice when the intake, exhaust, ignition, gearing, and jetting are matched correctly.
| Carburetor style | Best fit | Character | Shop |
|---|---|---|---|
| Original Bing / small original carb | Stock or near-stock Puch setups | Original feel, simple, limited airflow. | View Bing parts |
| AMAL / Arreche 17mm | Mild tuning and classic moped builds | Simple, compact, period-correct feeling, needs correct jets. | View AMAL 17mm View AMAL parts |
| Dellorto PHBG 17.5 / 19 / 21 | Broader tuning range and more adjustment options | More parts support and more tuning variables. | View PHBG parts |
| Polini CP / PWK / Mikuni TM | Sport and race-oriented builds | More flow potential, sharper response, more setup sensitivity. | View Polini parts |
Fitting tips before you ride
Before starting the engine, check that the carburetor is properly fitted and that the throttle and choke operate smoothly. Small installation problems can look like jetting problems once the engine is running.
Ready to install an AMAL / Arreche 17mm on your Puch?
Start with the correct carburetor, then match it with the right manifold, air filter, throttle cable and jets for your engine setup.
View the AMAL / Arreche 17mm carburetor Start rich, test carefully, and tune one change at a time.FAQ: AMAL / Arreche 17mm carburetor for Puch
Is the AMAL / Arreche 17mm good for a Puch Maxi?
It can be a good option for a mild Puch setup when the intake manifold, air filter, exhaust, ignition, and jetting are matched correctly. Always confirm the manifold size before ordering or installing.
Is this the same as an AMAL Concentric?
No. It uses classic AMAL-style slide-carburetor principles, but the Puch moped carburetor should be treated as an AMAL / Arreche moped carburetor, not the same as a full-size British Mark 1 Concentric motorcycle carburetor.
What jet should I use in the AMAL / Arreche 17mm?
There is no universal jet size. Start rich, check what jet is physically installed, and tune based on the complete engine setup. Cylinder, exhaust, air filter, ignition, fuel flow, and weather all affect the final jet.
What does carburetor circuit mean?
In this context, a circuit is a fuel/air pathway inside the carburetor that mainly works during a certain throttle range, such as idle, transition, needle range, or full throttle.
Why does my engine bog when I open the throttle?
A bog during throttle opening often points to the pilot-to-needle transition, throttle slide cutaway area, needle clip position, fuel flow, or an air leak. Diagnose by throttle position, not only by rpm.
Can I run an open air filter?
Yes, if it fits and seals correctly, but an open or less restrictive filter usually requires richer jetting. Do not install a freer-flowing filter and keep the old jetting without testing.
