How Mopeds Work – ENGINE

How mopeds work are very simple once the mechanics of the engine are make sense. Most vintage mopeds are powered by two-stroke engines. Two-stroke engines are very popular for these small displacement motorcycles. The engines are lightweight for the amount of power created.

The piston compresses the air and fuel mixture in the cylinder. On ignition from the spark plug, the piston is pushed down. On the pistons downward motion, the piston acts as an exhaust valve and then an intake valve. The combusted gasoline will exit through the exhaust port first. Then fresh gas and air will fill the cylinder and get compressed on the pistons travel up the cylinder. Then the process repeats unless there is no new gas or spark to the cylinder. Two-stroke engines complete this process in fractions of a second.

How Moped Works – Starting

Starting a moped can feel abnormal at first because they do not start with the push of a button, although there are some models that can. Most pedal mopeds are started with rear wheel motion.

One feature of a moped is the bicycle like pedals. They are used for starting the moped, a place for your feet while riding and an alternative for motion.

Starting a vintage moped depends on the manufacture of the engine. Some use a clutch lever that engages the engine and begins the two-stroke ignition process. Some start when the moped rear wheel moves at a speed greater than 5mph or so. Those might have a decompression lever to release some of the compression in the engine for easier starting. There are some that can be kick-started without any additional levers.

Here are some general steps for starting a moped:

Variated mopeds

Hold the decompression lever and begin to pedal the moped. When you begin to hear the engine combustion, release the lever while continuing to pedal.

Non-variated mopeds

Begin by riding the moped and building some momentum. With the forward motion pull on the clutch lever. This will activate the engine process.

Starting tips

An easy way to start a moped is to pedal it off of the center stand as fast as possible. Pull the clutch lever, the forward momentum will engage the clutch. Make sure you have fuel, your fuel valve is open and feeding fuel to the carburetor and that the kill switch is in the running position.

How Moped Work – Motion

All mopeds share similar engine mechanics. All mopeds use a crankshaft or crank for short. The crank links the piston, ignition and the motion mechanism in a sense.

There are various methods used to drive the rear wheel. After the engine is turned on, their transmissions are automatic. With a twist of the wrist air and fuel are fed into the engine and produce the power to move the moped. The more air and fuel forced into the engine the faster it will perform and increase the speed of movement.