Engine family RJAJC.049MCA

What this record says

Sold in the US by

Jiajue U.S.A. LLC

Engine built by

Zhejiang Jiajue

Vehicle category

Highway Motorcycle - Ia (<50cc)

Certificate numbers

RJAJC.049MCA-002

What the number itself says

Reading RJAJC.049MCA left to right: R is the model-year letter for 2024, JAJ is the three-character code the EPA assigned to Jiajue U.S.A. as certificate holder, C marks a highway (street-legal) certification, .049 is the displacement in litres, so 49cc and MCA is Jiajue U.S.A.'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 Jiajue U.S.A. submitted for this family (model JJ49QT) carried engine code JJ1P39QMB-A. In the Chinese engine-model convention that reads as one cylinder, horizontal (flat) 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 throttle-body fuel injection, with an oxygen sensor for closed-loop fuelling, run by an engine control module (ECM). There is a catalytic converter in the exhaust, recorded as "Three Way Catalyst (TWC), single-bed, closed-loop warm up".

Rated power on the record is 1.9 kW (about 3 hp) at 7,500 rpm, driving through a CVT (belt and variator).

Engine code on test vehicle

JJ1P39QMB-A

Nominal bore (from the code)

39 mm · implied stroke ≈ 41 mm

Cylinders / valves

1 · 2 per cylinder

Cycle

four-stroke

Fuel delivery

throttle-body fuel injection

Oxygen sensor

yes (closed loop)

Engine control

ECM

Catalytic converter

Three Way Catalyst (TWC), single-bed, closed-loop warm up

Rated power

1.9 kW (≈3 hp)

Rated speed

7,500 rpm

Transmission

CVT (belt and variator)

Sales area

49S

Vehicle built by

Zhejiang Jiajue Motorcycle Manufacturing Co.,Ltd

Test vehicle model

JJ49QT

Filing history and where it was sold

Jiajue U.S.A. filed one certificate under this family, for model year 2024, sold as 49-state (not certified for sale in California).

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

Certified emission levels: CO 0.9, HC 0.4 g/km.

Models certified under RJAJC.049MCA

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.

JJ49QT · JJ49QT-10 · JJ49QT-11 · JJ49QT-12 · JJ49QT-13 · JJ49QT-14 · JJ49QT-15 · JJ49QT-16 · JJ49QT-17 · JJ49QT-18 · JJ49QT-19 · JJ49QT-2 · JJ49QT-3 · JJ49QT-4 · JJ49QT-5 · JJ49QT-6 · JJ49QT-7 · JJ49QT-8 · JJ49QT-9

Other American badges on engines from the same factory

• Zhejiang Jiajue · 49-50cc2 American brands · 2009–2026
• Zhejiang Jiajue · 150cc4 American brands · 2009–2025