The GY6 engine design is a

four-stroke A four-stroke (also four-cycle) engine is an internal combustion (IC) engine in which the piston completes four separate strokes while turning the crankshaft. A stroke refers to the full travel of the piston along the cylinder, in either directio ...

single-cylinder in a near horizontal orientation that is used on a number of small motorcycles or scooters made in Taiwan, China, and other southeast Asian countries. It has since become a generic technology. Kymco went on to produce Honda clones such as the Pulsar (CB125), made to Honda standards, as part of their range. 24- The four stroke engine for 125cc scooters. Honda's KCW125 (the commercial name in Japan is "Spacy") was modified by Taiwan's Kwang Yang Motor Co., Ltd. (KYMCO), under Honda's consultancy, and became a standard model called the GY6 which various Taiwan makers imitated and minor-changed. Apparently, vehicles of this model were imported from Taiwan by various manufacturers and traders, and spread mainly in the southern coastal regions of China. Source link: https://ir.ide.go.jp/?action=repository_action_common_download&item_id=40179&item_no=1&attribute_id=26&file_no=1

Configuration

The GY6 single is forced air-cooled, with a chain-driven overhead camshaft and a crossflow

hemi Hemi may refer to: People Surname * Jack Hemi (1914–1996), New Zealand freezing worker, rugby union and league player, shearer * Ronald Hemi (1933–2000), New Zealand rugby union player Given name * Hemi Bawa, Indian painter and sculptor * H ...

cylinder head. Fuel metering is by a single constant-velocity style sidedraft

carburetor A carburetor (also spelled carburettor) is a device used by an internal combustion engine to control and mix air and fuel entering the engine. The primary method of adding fuel to the intake air is through the venturi tube in the main meteri ...

, typically a Keihin CVK clone or similar. Ignition is by capacitor discharge ignition (CDI), with a magnetic trigger on the flywheel. Because the trigger is on the flywheel instead of the camshaft, the ignition will fire on both the compression and exhaust strokes, making it a wasted spark ignition. An integrated magneto provides 50 V AC power for the CDI system and 20-30 V AC rectified and regulated to 12 V DC for chassis accessories such as lighting, and to charge a battery. It includes an integrated

swingarm A swingarm, or "swinging arm" (UK), originally known as a swing fork or pivoted fork, is a single or double sided mechanical device which attaches the rear wheel of a motorcycle to its body, allowing it to pivot vertically. The main component of ...

, which houses a centrifugally controlled

Continuously variable transmission A continuously variable transmission (CVT) is an automatic transmission that can change seamlessly through a continuous range of gear ratios. This contrasts with other transmissions that provide a limited number of gear ratios in fixed steps. T ...

(CVT) using a rubber belt sometimes called a VDP. At the rear of the swingarm, a centrifugal clutch connects the transmission to a simple integral gear-reduction unit. There is no clutch of any kind between the CVT and the crankshaft; it is engaged via a centrifugal clutch at the rear pulley in the same fashion as Vespa Grande, Bravo and variated

Ciao ''Ciao'' ( , ) is an informal salutation in the Italian language that is used for both "hello" and "goodbye". Originally from the Venetian language, it has entered the vocabulary of English and of many other languages around the world. Its du ...

model, as well as Honda Camino/Hobbit scooters/ mopeds. An electric starter, backup kick-starter, and rear brake hardware is also housed in the swingarm.

References

https://ir.ide.go.jp/?action=repository_action_common_download&item_id=40179&item_no=1&attribute_id=26&file_no=1

Configuration

References

Further reading