EPA engine family

Engine family SAMSC.169MCB

If this code is printed on your emission label, this is your machine's federal record: sold under Amstar Motors LLC, with an engine built by Taizhou Zhongneng (ZNEN), certified as street-legal scooters and motorcycles.

Displacement: —
Model years: 2025
Models certified: 18
Certificates: 1

What this record says

Sold in the US by: Amstar Motors LLC
Engine built by: Taizhou Zhongneng (ZNEN)
Vehicle category: Highway Motorcycle - Ib (50-169cc)
Certificate numbers: SAMSC.169MCB-005

What the number itself says

Reading SAMSC.169MCB left to right: S is the model-year letter for 2025, AMS is the three-character code the EPA assigned to Amstar Motors as certificate holder, C marks a highway (street-legal) certification, .169 is the displacement in litres, so 169cc and MCB is Amstar Motors' own sequence for that year. Nothing in the number names the factory — that comes from the certificate itself.

The engine, as described on the certificate

The test vehicle Amstar Motors submitted for this family (model TIGER 175) carried engine code BN161QMK-A. In the Chinese engine-model convention that reads as one cylinder with a nominal 61 mm bore, QMK series.

The certificate describes a four-stroke, single-cylinder engine with 2 valves per cylinder fed by carburettor. There is a catalytic converter in the exhaust, recorded as "TWC, single bed, open loop". The head carries a pulse secondary-air (PAIR) valve.

Rated power on the record is 8 kW (about 11 hp) at 7,500 rpm, driving through a CVT (belt and variator).

Engine code on test vehicle: BN161QMK-A
Nominal bore (from the code): 61 mm
Cylinders / valves: 1 · 2 per cylinder
Cycle: four-stroke
Fuel delivery: carburettor
Oxygen sensor: no
Engine control: other
Catalytic converter: TWC, single bed, open loop
Air injection: PAIR
Rated power: 8 kW (≈11 hp)
Rated speed: 7,500 rpm
Transmission: CVT (belt and variator)
Sales area: 50S
Vehicle built by: Taizhou Zhongneng Motorcycle Co.,Ltd.
Test vehicle model: TIGER 175

Filing history and where it was sold

Amstar Motors filed one certificate under this family, for model year 2025, sold as 50-state, California included.

The vehicle itself is recorded as built by the same company, Taizhou Zhongneng Motorcycle Co.,Ltd. in China — engine and chassis from one source.

Certified emission levels: CO 7.1, HC 0.3 g/km.

What this configuration means when you shop for parts

Amstar Motors certified the BN161QMK-A with a carburettor, so the fuel-side wear items are the carburettor, its jets and float needle, the intake boot and the choke. The 61 mm bore in the code gives the engine size, not the carburettor size — measure the intake bore and the mounting on the BN161QMK-A before ordering.

The CVT behind the BN161QMK-A makes its drive belt, variator rollers and clutch shoes the consumables, so measure the old belt on the TIGER 175 rather than ordering by displacement.

The PAIR valve Amstar Motors lists on the BN161QMK-A is an emissions part; its hoses perish and are the usual cause of popping on the overrun.

The exhaust on Amstar Motors' SAMSC.169MCB carries a catalyst, so a replacement silencer without one changes what the BN161QMK-A was certified with.

Other records carrying the same engine code

Amstar Motors certified an engine with this code under 6 other family numbers — the same engine filed again in another year, or in an off-road and a street version:

A shared code from the same factory is a strong search lead. From a different factory it is as often a naming coincidence. Either way it narrows the search; it does not settle it — measure before you buy.

Models certified under SAMSC.169MCB

Every model designation the importer listed on this certificate. If your machine's model name appears here, this is the right record — even if the name on the bodywork is slightly different.

Angel 175 · BELLA 150 · Coral 175 · Cruise 175 · Frigate 175 · K25 150 · K26 150 · Monkey 175 · NMAX 175 · S-JOG 150 · S-JOG 175 · Sand 150 · Tiger 175 · V11 175 · V12 175 · Valiant 175 · Veracruz 150 · Veracruz 175

Other American badges on engines from the same factory

Related in the registry

Source. US EPA annual certification data — EPA Certified Highway Motorcycle Test Results, MY2006-present; EPA Certified Off-Road Motorcycle / ATV / UTV / Rec Vehicle, MY2006-present. Retrieved 2026-09-07. Full provenance and method.