How can i tell if my lawn mower engine is a 2 stroke or 4 stroke?

Question

This is basically so that I can find a better way to explain this to my friend, and to settle a bet with another friend. Thanks

Answer 1

Does it have a dip stick? Do you add oil to the gas? I am betting that it is a four stroke. Not many 2 stroke lawnmowers. What is the engine brand? Briggs, Tecumseh?

Answer 2

Gas engines have pistons that go up and down in cylinders, some cars are 4 cylinder, some 6 and others 8, most economical cars are 4 cylinder. Think of when you get a shot at the doctors, he sticks the needle in you and presses down with his thumb whichs forces a piston in the syringe down a cylinder thus pushing the medicine into your arm, butt whatever. You ever have blood taken? The doctor raises the piston after sticking you and this sucks the blood into the cylinder. In a engine the cylinders and pistons look like the syringe (without the needle) and act the same way. Don't think of 4 cylinder engines right now. Just think of a one cylinder engine. Piston moves down and sucks gas and air into the cylinder through an intake valve where the needle would be on the syringe (INTAKE STROKE.) Then piston moves up, valve closes and gas/air are squeezed inside the cylinder (COMPRESSION STROKE). Then the Spark Plug fires igniting the gas/air and the exsplosion in the cylinder forces the piston back down again. (POWER STROKE) Now to get rid of the burnt gas/air in the cylinder, the piston goes up again and an exhaust valve located right next to the intake valve opens. The rising piston pushes the exhaust out through this valve (just like the medicine in the syringe) and it goes to your muffler and out the tailpipe to cause global warming. (EXHAUST STROKE). Then the whole thing repeats. Count the strokes; INTAKE, COMPRESSION, POWER and EXHAUST, 4 right? Thats the 4-stroke engine. Now the 2-stroke engine is simpler because there are no intake or exhaust valves. Hence there is no intake or exhaust Stroke. Without the intake and exhaust strokes only the compression and power stroke remain, 2 strokes. So this is called the 2-stroke engine. How does the gas/air mixture get in and out of the 2 strokes cylinder without valves? Well some genius cut holes in the cylinder walls which are uncovered and covered by the piston going up and down at precisely the right time to let the fuel and exhaust out. Why do you have to mix oil in the gas for the 2-stroke engine? Because in order to make the engine even simpler. The 2-stroke engine has no oil pump, oil pan, oil filter and not even a dipstick! All of the lubrication the engine gets, comes from the oil mixed in the gas. If you boo boo and forget to mix oil with the gas! Kiss that engine goodbye because it has no lubrication and will seize. The oil is burnt with the gas/air after lubricating the cylinder/piston and this is why 2-stroke engines smoke. As you can see the 2-stroke is less complicated, has fewer parts and this makes them easy/cheap to make. So you put these little suckers in all sorts of things like chainsaws, weed wackers, leaf blowers etc. Most lawn mowers are 4-stroke. The LawnBoy lawnmower is a 2-stroke however. 2-strokes are more polluting because of the oil being burned.

Answer 3

If you need to mix oil with the gasoline or fill a separate oil tank each time you fill the gas tank, it is 2 stroke. Otherwise it is 4 stroke.

If the exhaust blows blue smoke it is 2 stroke. If it is grey smoke it is 4 stroke.

Those are the easiest ways I can think of.

Bert

Answer 4

I've never heard of a 2 stroke lawn mower, but if you have one then you'll have to mix oil with the gas.

Answer 5

look all over the base of the engine for any place to unscrew a bolt to pour oil in or look on the bottom for a oil drain hole,if you find them,it is a four stroke,if not,it is a two stroke with reeds valves

Answer 6

A two stroke will not have an oil reservoir. The oil gas mix act as the lubricant

Answer 7

2 Stroke Lawn Mowers

Answer 8

The four stroke does not have a carburetor..