EPA engine family

Engine family BYYGC0.15BZU

If this code is printed on your emission label, this is your machine's federal record: sold under Yiying Motorcycle Inc., with an engine built by Benzhou Vehicle Industry Group Co.,Ltd, certified as street-legal scooters and motorcycles.

Displacement: —
Model years: 2011
Models certified: 16
Certificates: 1

What this record says

Sold in the US by: Yiying Motorcycle Inc.
Engine built by: Benzhou Vehicle Industry Group Co.,Ltd.
Vehicle category: Highway Motorcycle - Ib (50-169cc)
Certificate numbers: BYYGC0.15BZU-001

The engine, as described on the certificate

The test vehicle Yiying Motorcycle submitted for this family (model YY150QT-10) carried engine code BZ157QMJ. In the Chinese engine-model convention that reads as one cylinder with a nominal 57 mm bore, QMJ 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 7.2 kW (about 10 hp) at 7,500 rpm, driving through a CVT (belt and variator).

Engine code on test vehicle: BZ157QMJ
Nominal bore (from the code): 57 mm
Cylinders / valves: 1 · 2 per cylinder
Cycle: four-stroke
Fuel delivery: carburettor
Oxygen sensor: no
Catalytic converter: TWC, single bed, open loop
Air injection: PAIR
Rated power: 7.2 kW (≈10 hp)
Rated speed: 7,500 rpm
Transmission: CVT (belt and variator)
Sales area: 50S
Vehicle built by: Benzhou Vehicle Industry Group Co.,Ltd.
Test vehicle model: YY150QT-10

Filing history and where it was sold

Yiying Motorcycle filed one certificate under this family, for model year 2011, sold as 50-state, California included.

The vehicle itself is recorded as built by the same company, Benzhou Vehicle Industry Group Co.,Ltd. in China — engine and chassis from one source.

Certified emission levels: CO 3.8, HC 0.2 g/km.

What this configuration means when you shop for parts

Yiying Motorcycle certified the BZ157QMJ with a carburettor, 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 BZ157QMJ before ordering.

The CVT behind the BZ157QMJ makes its drive belt, variator rollers and clutch shoes the consumables, so measure the old belt on the YY150QT-10 rather than ordering by displacement.

The PAIR valve Yiying Motorcycle lists on the BZ157QMJ is an emissions part; its hoses perish and are the usual cause of popping on the overrun.

The exhaust on Yiying Motorcycle's BYYGC0.15BZU carries a catalyst, so a replacement silencer without one changes what the BZ157QMJ was certified with.

Other records carrying the same engine code

Yiying Motorcycle 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:

Other certificate holders whose test vehicle carried the same engine code:

Cmsi Inc.AYPXC0.15AIM2010 · same engine factory
North American Imports,LLCANAMC0.15BZU2010 · same engine factory
North American Imports,LLC9NAMC0.15BZU2009 · 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 BYYGC0.15BZU

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.

Yiying YY125T-10 · Yiying YY125T-11 · Yiying YY125T-12 · Yiying YY125T-19 · Yiying YY125T-31 · Yiying YY125T-32 · Yiying YY125T-6 · Yiying YY150T-10 · Yiying YY150T-12 · Yiying YY150T-19 · Yiying YY150T-25 · Yiying YY150T-26 · Yiying YY150T-31 · Yiying YY150T-32 · Yiying YY150T-6 · Yiying YY150T-7

Other American badges on engines from the same factory

Benzhou Vehicle Industry Group Co.,Ltd. · 49-50cc4 American brands · 2007–2015

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.