what is the difference between a 2 stroke and a four stroke?

Answer 1

If you mean what is the difference in performance:
2 stroke motors are lighter, and have a greater power-to weight ratio (a 125 cc two stroke is roughly equivalent to a 200cc four stroke). Two strokes also have fewer moving parts.
BUT: The power delivery is very different. two strokes are higher on power but much lower in torque than 4 strokes, and four strokes have a much more manageable 'power band (the range of usable power is over a much wider rev range). As a result, four strokes are much smoother and easier to ride. With the larger motors, four strokes have become almost universal. two strokes are still very popular on smaller bikes, and especially small capacity scooters.

Answer 2

The difference is how many times the piston has to make a "stroke" in a cycle.

A two stroke will make a power/exhaust stroke, and an intake/ compression stroke.

There are holes cut in the sides of the cylinders that allow the exhaust out and push the air/fuel mix in.

On a 4 stroke engine the strokes are broken down singularly.

There is an intake stroke:
The exhaust valve is closed, and the intake valve opens. As the piston moves downward it draws in the air/fuel mix.

The compression stroke:
All valves close and the piston is forced upwards by the other pistons. This causes the air/fuel mix to get squeezed.
Once the piston reaches towards the top of this stroke the spark plug fires.

The power stroke:
The air/fuel mix explodes and forces the piston back downward. Both valves remain closed.

The exhaust stroke:
Once the piston reaches the bottom of the power stroke the exhaust valve opens. The piston is forced back upwards by the other pistons, and the exhaust gasses get pushed out.
The exhaust valve closes, and the cycle starts all over again.

The 2 stroke engine does not have, nor need, a valve system. The 4 stroke does.

Answer 3

Two strokes take mixed fuel or have oil Injection, Four strokes will have a Dipstick under the cowling to check the oil just like a car. Four stroke has Valves eather over head or flat top, And for the most part two stroke will have a flat head with the spark plug in the middle. And if it is running a Two stroke will Blow some Blue smoke when you start it. and sometimes at idle depending on the year of the motor the new two strokes are very clean, Hope this helps you out a little

Answer 4

AGAIN...here it is..

a 4 stroke goes like this...
http://www.keveney.com/otto.html

and the two stroke engine goes like this...
http://www.keveney.com/twostroke.html

Answer 5

the amount of pistons cycles