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The Scooter Parts Registry

EPA engine family

Engine family 9YYGC0.28BZU

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
2009
Models certified
18
Certificates
1

What this record says

Sold in the US by
Yiying Motorcycle Inc.
Vehicle category
Highway Motorcycle - II (170-279cc)
Certificate numbers
9YYGC0.28BZU-003

The engine, as described on the certificate

The test vehicle Yiying Motorcycle submitted for this family (model YY300T) carried engine code BZ173MN. In the Chinese engine-model convention that reads as one cylinder with a nominal 73 mm bore, MN series.

The certificate describes a four-stroke, single-cylinder engine with 2 valves per cylinder fed by carburettor, run by an ignition control module (CDI-type ignition). 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 13.5 kW (about 18 hp) at 7,000 rpm, driving through a CVT (belt and variator).

Engine code on test vehicle
BZ173MN
Nominal bore (from the code)
73 mm
Cylinders / valves
1 · 2 per cylinder
Cycle
four-stroke
Fuel delivery
carburettor
Oxygen sensor
no
Engine control
ICM
Catalytic converter
TWC, single bed, open loop
Air injection
PAIR
Rated power
13.5 kW (≈18 hp)
Rated speed
7,000 rpm
Transmission
CVT (belt and variator)
Sales area
50S
Vehicle built by
Benzhou Vehicle Industry Group Co., Ltd
Test vehicle model
YY300T

Filing history and where it was sold

Yiying Motorcycle filed one certificate under this family, for model year 2009, 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 2.1, HC 0.8 g/km.

Other records carrying the same engine code

Yiying Motorcycle certified an engine with this code under 2 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 9YYGC0.28BZU

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 YY250T · Yiying YY250T-2 · Yiying YY250T-2A · Yiying YY250T-4 · Yiying YY250T-4A · Yiying YY250T-5 · Yiying YY250T-5A · Yiying YY250T-6 · Yiying YY250T-6A · Yiying YY250T-8 · Yiying YY250T-8A · Yiying YY250TA · Yiying YY300T · Yiying YY300T-2 · Yiying YY300T-3 · Yiying YY300T-4 · Yiying YY300T-5 · Yiying YY300T-6

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.