Engine family SAPXC.249MC2

What this record says

Sold in the US by

Apex Motosports Inc

Engine built by

Yongkang Jiayue Industry Co., Ltd.

Vehicle category

Highway Motorcycle - II (170-279cc)

Certificate numbers

SAPXC.249MC2-002

What the number itself says

Reading SAPXC.249MC2 left to right: S is the model-year letter for 2025, APX is the three-character code the EPA assigned to Apex Motosports as certificate holder, C marks a highway (street-legal) certification, .249 is the displacement in litres, so 249cc and MC2 is Apex Motosports' 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 Apex Motosports submitted for this family (model HRX250) carried engine code 174FMN. In the Chinese engine-model convention that reads as one cylinder with a nominal 74 mm bore, FMN series. Against the certified 249cc that implies a stroke of roughly 58 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 14 kW (about 19 hp) at 8,000 rpm, driving through a 4-speed manual gearbox.

Engine code on test vehicle

174FMN

Nominal bore (from the code)

74 mm · implied stroke ≈ 58 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

14 kW (≈19 hp)

Rated speed

8,000 rpm

Transmission

4-speed manual gearbox

Sales area

50S

Vehicle built by

Yongkang Eagle Motor Co., LTD.

Test vehicle model

HRX250

Filing history and where it was sold

Apex Motosports filed one certificate under this family, for model year 2025, sold as 50-state, California included.

The vehicle itself is recorded as built by the same company, Yongkang Eagle Motor Co., LTD. in China — engine and chassis from one source.

Certified emission levels: CO 3.9, HC 0.2 g/km.

Models certified under SAPXC.249MC2

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.

HRC250AIR · HRC250R · HRC250RS · HRE250AIR · HRE250EX · HRE250PRO · HRE250R · HRE250RC · HRE250RS · HRE250S · HRE250SE · HRE250SX · HRE250X · HRX250 · HRX250AIR · HRX250C · HRX250ES · HRX250EX · HRX250R · HRX250SR · HRX250X