Engine family AYYGC.049BZU

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 - Ia (<50cc)

Certificate numbers

AYYGC.049BZU-001

What the number itself says

Reading AYYGC.049BZU left to right: A is the model-year letter for 2010, YYG is the three-character code the EPA assigned to Yiying Motorcycle as certificate holder, C marks a highway (street-legal) certification, .049 is the displacement in litres, so 49cc and BZU is Yiying Motorcycle's 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 Yiying Motorcycle submitted for this family (model YY50QT) carried engine code BZ139QMB. In the Chinese engine-model convention that reads as one cylinder with a nominal 39 mm bore, QMB series. Against the certified 49cc that implies a stroke of roughly 41 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 2.2 kW (about 3 hp) at 7,500 rpm, driving through a CVT (belt and variator).

Engine code on test vehicle

BZ139QMB

Nominal bore (from the code)

39 mm · implied stroke ≈ 41 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

2.2 kW (≈3 hp)

Rated speed

7,500 rpm

Transmission

CVT (belt and variator)

Sales area

49S

Vehicle built by

Benzhou Vehicle Industry Group Co.,Ltd.

Test vehicle model

YY50QT

Filing history and where it was sold

Yiying Motorcycle filed one certificate under this family, for model year 2010, sold as 49-state (not certified for sale in California).

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 0.4 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:

• 9YYGC.049BZU (2009)
• FYYGC.049BZU (2015)

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

• North American Imports,LLCANAMC.049BZU2010 · same engine factory
• North American Imports,LLC9NAMC.049BZU2009 · 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 AYYGC.049BZU

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 YY50QT · Yiying YY50QT-10 · Yiying YY50QT-12 · Yiying YY50QT-15 · Yiying YY50QT-21 · Yiying YY50QT-25 · Yiying YY50QT-26 · Yiying YY50QT-28 · Yiying YY50QT-31 · Yiying YY50QT-32 · Yiying YY50QT-33 · Yiying YY50QT-5 · Yiying YY50QT-6 · Yiying YY50QT-7 · Yiying YY50QT-8 · Yiying YY50QT-9

Other American badges on engines from the same factory

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