EPA engine family

Engine family MAMSC0.15MC1

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: 150cc
Model years: 2021
Models certified: 26
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: MAMSC0.15MC1-001

The engine, as described on the certificate

The test vehicle Amstar Motors submitted for this family (model R8 150) carried engine code BN157QMJ. In the Chinese engine-model convention that reads as one cylinder with a nominal 57 mm bore, QMJ series. Against the certified 150cc that implies a stroke of roughly 59 mm — a sanity check for a piston or cylinder listing, not a published figure.

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 6.2 kW (about 8 hp) at 7,500 rpm, driving through a CVT (belt and variator).

Engine code on test vehicle: BN157QMJ
Nominal bore (from the code): 57 mm · implied stroke ≈ 59 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: 6.2 kW (≈8 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: R8 150

Filing history and where it was sold

Amstar Motors filed one certificate under this family, for model year 2021, 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 10.1, HC 0.3 g/km.

What this configuration means when you shop for parts

Amstar Motors certified the BN157QMJ with a carburettor at 150cc, so the fuel-side wear items are the carburettor, its jets and float needle, the intake boot and the choke. The 57 mm bore in the code gives the engine size, not the carburettor size — measure the intake bore and the mounting on the BN157QMJ before ordering.

The CVT behind the BN157QMJ makes its drive belt, variator rollers and clutch shoes the consumables; belt length and width vary between 150cc machines, so measure the old belt on the R8 150 rather than ordering by displacement.

The PAIR valve Amstar Motors lists on the BN157QMJ is an emissions part; its hoses perish and are the usual cause of popping on the overrun.

The exhaust on Amstar Motors' MAMSC0.15MC1 carries a catalyst, so a replacement silencer without one changes what the BN157QMJ was certified with.

Other records carrying the same engine code

Amstar Motors certified an engine with this code under 16 other family numbers — the same engine filed again in another year, or in an off-road and a street version:

Other certificate holders whose test vehicle carried the same engine code (10 of 59 shown):

AA Powersports Inc.9ASRC0.15ZNE2009 · same engine factory
Baja Inc.9BJMC0.15ZNE2009 · same engine factory
Bintelli LLCGGTRC0.15MC12016 · same engine factory
Bintelli LLCFGTRC0.15ZNE2015 · same engine factory
Bintelli LLCEGTRC0.15ZNE2014 · same engine factory
Bintelli LLCDGTRC0.15ZNE2013 · same engine factory
BMS Motorsports, Inc.SBMSC0.15MC12025 · same engine factory
BMS Motorsports, Inc.RBMSC0.15MC12024 · same engine factory
BMS Motorsports, Inc.PBMSC0.15MC12023 · same engine factory
BMS Motorsports, Inc.NBMSC0.15MC12022 · same engine factory

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 MAMSC0.15MC1

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.

Bull 150 · Canoe 150 · Coral 150 · F10 · F11 · Fighter 150 · Frigate 150 · JOC 150 · Lightning 150 · Marshal 150 · R-X 150 · R8 150 · Racestar 150 · Roguestar 150 · Trophy 150 · Veracruz 150 · ZN150T-30A · ZN150T-50 · ZN150T-7F · ZN150T-7G · ZN150T-7H · ZN150T-E · ZN150T-E3 · ZN150T-G · ZN150T-H · ZN150T-K

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.