Puch Maxi / Newport

History

The Puch Maxi arrived in 1969 from Graz, Austria, and became the default US moped — on the order of ~1.8 million built before production wound down. A sturdy pedal frame plus the bulletproof E50 or ZA50 engine gave campus transport that could be fixed with hand tools. Dealers sold them as cheap transportation; today survivors are project bikes, daily riders, and show pieces.

Newport is the US trim name on many tanks. Mechanically it is the same Maxi family — do not order parts by tank badge alone. American tuning culture centered on the E50: Bing carbs, clutch shoes, expansion chambers, and 70 cc kits. Parts depth is the platform’s superpower: Treatland, 1977 Mopeds, Myrons, and swap-meet frames keep rusty projects alive.

Gallery uses three different assets (street bike, engine ID pair, kit parts). The hero loop is a separate Imagine cinematic still — not repeated below.

E50 vs ZA50 — identify before you order parts

Pop the right-side engine cover and look at the shape:

• E50 — single-speed. One centrifugal clutch in the bell. Left lever disengages for pedal start; shoes grab by RPM. Rounder transmission area; tune shoe weight and springs, not roller weights.
• ZA50 — automatic two-speed inside the cases. First and second engage by internal centrifugal clutches — no shift lever. Cover is noticeably more rectangular. Fluid, pucks, and gear-tooth counts matter as much as jetting.

Both are piston-ported from the factory. Performance reed kits (Polini, Athena AJH, etc.) need case machining — not a bolt-on Stage 2 part. Some ZA50s had oil injection; most US bikes are premix in the tank.

1 HP, 1.5 HP, and 2 HP

Stock speed is roughly ~20 / ~25 / ~30 mph by class. The rating shows up in jets, manifold size, head gasket, and (on ZA50) internal gearing:

• 1 HP — restricted intake port, thick head gasket, small manifold, small jets; ZA50 often taller internal ratios.
• 1.5 HP — 12 mm manifold class, intermediate Bing setup.
• 2 HP — 14 mm manifold, thin/no head gasket, larger jets — factory “open” class.

Puch published a factory 1.5 → 2 HP conversion path (manifold, gasket, airbox pipe, main/slide/needle, exhaust drill pattern). A true 1 HP jug is a different fight — plan cylinder work, not just a jet swap. Details and photos: 1 HP derestrict guide.

Service habits that matter

• E50 clutch — glazed shoes slip no matter what jet you run. Blue springs are a common floor for piped street builds; shoe weight changes grab RPM.
• ZA50 trans — correct ATF, fresh shift pucks, and matched 1 HP vs 2 HP gear clusters. Wrong fluid or mixed tooth counts ruin shift quality.
• Bing jetting — know your carb size and HP class before copying forum jets. Air leaks at the manifold mimic lean symptoms.
• Timing — set with a light off a real TDC mark (flywheel rim ≈ 1 mm per degree). Stock E50 often ~14–17.5° BTDC; ZA50 advance direction is reversed vs E50.
• Premix — commonly ~50:1; richer on kits. See the oil mix calculator.

Buying used

1. Confirm E50 vs ZA50 (cover shape / one clutch vs two-speed behavior under load).
2. Read the data plate for HP class; assume 1 HP is restricted until you see the jug and manifold.
3. Compression warm vs a known-good runner; listen for exhaust leaks; check chain/sprockets and frame rust at seat tube and down tube.
4. Budget clutch shoes or ZA50 fluid/pucks, plug, fuel lines, and a Bing clean on any “runs good” ad.
5. Title/VIN match — campus bikes often have messy paperwork.

Performance paths

Mild derestrict + jetting, mid 70 cc kit + pipe + clutch, wild reed/port work — staged parts lists live in the build database. Match pipe peak RPM to clutch grab and jetting; do not start with a race pipe on a restricted 1 HP jug.

FAQ

What is the difference between a Puch E50 and ZA50?

The E50 is a single-speed engine with one centrifugal clutch. The ZA50 is an automatic two-speed with internal clutches and a more rectangular cover. Both are stock piston-port.

Is Newport different from Maxi?

Newport is the common US trim name on many tanks. Mechanically it is the same Maxi family — confirm E50 vs ZA50 and HP class before ordering parts.

What premix ratio should I run on a Puch Maxi?

Stock Puchs commonly run about 50:1 with quality synthetic two-stroke oil. Kitted and break-in builds often run richer (for example 32:1–40:1).

How much does a Puch Maxi cost?

US project and running bikes often fall roughly in the $500–$1,400 range depending on condition, title, and how restricted the top end still is.