Quick specs

Displacement49 cc class (A35 stock ~38×43 mm)
Final driveChain + automatic 2-speed gearbox
A35 inductionReed-valve · Dellorto SHA 14/12 · stock ~#53 main
A55 (Revival)Piston-port · Dellorto PHVA 14 · stock ~#55 main / #25 pilot
PremixTypically 50:1 quality synthetic (no oil pump on most US bikes)
Spark (A35)NGK BR6HS (CDI) or B6HS (points); gap ~0.8 mm
Chain slack~10 mm free play (up/down)
US street priceRoughly $800–$2,200 depending on condition and Revival trim
Black Tomos Sprint — different model photo from hero
Tomos Sprint (period photo) — not the same frame as the hero still. Confirm reed A35 vs piston-port A55 on the engine, not the tank badge.

History

Tomos (Tovarna Motornih Koles Sežana) built mopeds long after many European plants quit. US buyers in the 1990s–2010s got chain-drive, pedal-capable 49 cc machines — Targa, Sprint, Bullet, and later the Revival — while scooter culture went CVT. When the factory closed, prices climbed: a sorted runner is a serious purchase, not a throwaway barn find.

Slovenian frames and cases generally hold up when chain tension and gearbox fluid are maintained. The brand’s US reputation is “last real moped you could buy new” — still true in collector and commuter circles for A35/A55 frames.

Maroon Tomos Revival A55 parked on grass 1993 Tomos Bullet TT LX A35 Tomos clutch and transmission service detail

Gallery uses three different assets (Revival bike, Bullet, service detail). Side card is Sprint; hero is a separate Imagine cinematic still — no image file is repeated on the page.

A3, A35, and A55 — don’t guess

On many US frames, VIN digits help identify the model. Common patterns (always verify with a manual and the engine itself):

  • A3 / A3N — older Sprint and classic-line engines. Some parts overlap A35; not everything swaps.
  • A35 — Targa, Sprint TT, Bullet and related (common VIN codes in the 44–49 / 56 range, etc.). Roughly 1991–2006. Reed-valve cylinder, Dellorto SHA 14/12, stock main often around #53.
  • A55 — Revival and later US Tomos (VIN 26 is a common A55 Revival marker). From ~2003. Piston-ported nikasil cylinder, Dellorto PHVA 14, stock roughly #55 main / #25 pilot. Exhaust port angle differs — A35 pipes often need bending or A55-specific hardware.

Revival is A55, not A35. Streetmate is a different Tomos line. Order reeds, cylinders, and manifolds by engine code, not tank badge alone.

A35 reed vs A55 piston-port How intake differs — A35 reed vs A55 piston-port A35 — Reed valve Case Reed SHA Petals open on vacuum Soft timing · Helmholtz-friendly Service: reed block gaskets A55 — Piston port Bore PHVA Skirt opens/closes port Hard timing · open-period waves Service: port edge + PHVA jets
Technical diagram (inline SVG). Use intake length tuning in reed mode for A35 and piston-port mode for A55.

Drive train — chain, not belt

A35 and A55 use chain final drive and an automatic two-speed transmission inside the engine cases. That is not a scooter CVT and not a belt to the rear wheel. Set chain slack to about 10 mm free play and check it every few hundred miles. Hooked sprockets mean replace chain and sprockets as a set.

Service habits that actually matter

  • Gearbox ATF — separate from premix. Type A (Dexron) or Type F is typical. A35: drain bottom plug, fill until fluid weeps from the side level screw (easy to strip). A55: roughly ~10 fl oz (300 cc) when the level screw is hard to use.
  • Two-speed clutch — slip, hang in first, or lazy upshift: pucks, springs/shims, and wrong gearbox oil are the usual suspects.
  • Carb — bogging off idle is often a dirty SHA (A35) or PHVA (A55). Clean before chasing random jet sizes; jet numbers do not match Bing.
  • A35 reed block — leaky gaskets = oily cases and soft low-end. A55 has no reed cage — different top-end parts.
  • Exhaust gasket — blowout is loud and lean; fix studs and gasket before jetting.

Premix is usually 50:1 with quality synthetic 2-stroke oil. See the oil mix calculator.

Buying used

  1. Confirm A35 vs A55 (VIN + look for reed cage vs piston-port jug) before ordering a kit or pipe.
  2. Warm compression vs a known-good runner — very low numbers (often discussed under ~90 PSI warm) point at top-end work.
  3. Watch the two-speed shift under load; listen for exhaust leaks; check chain/sprockets and tank rust.
  4. Budget ATF service, plugs, fuel lines, and a carb clean on any “runs good” ad.

Performance paths

Tuning is clutch + jet + pipe logic, not variator weights. Mild sorted stock is often ~30–35 mph; mid 70cc builds ~40–45; wild ported/reed setups higher with careful jetting and break-in. Do not bolt an A35 pipe to an A55 without checking port angle (~25° on A55). Full staged lists live in the build database.

Full platform guide → Mild / mid / wild builds → Manuals & PDFs → Intake calculator →

FAQ

Is a Tomos Revival an A35?
No. US Revival models are typically A55 piston-port engines. A35 is the earlier reed-valve family.
Does a Tomos use a belt like a scooter?
No. A35/A55 use a chain and an internal automatic two-speed gearbox. Service the chain and ATF.
Can I put A35 parts on an A55?
Some wear items overlap; cylinders, reeds, manifolds, and exhaust angles often do not. Match the engine code.
What premix ratio should I run?
Most owners run about 50:1 with quality synthetic two-stroke oil unless a kit maker specifies richer for break-in.