What is the diff. between a 2stroke 7 4 stroke engine in motorcycles?

Answer 1

I would google this one to find a good solid answer with pictures as it is easier to understand with them.

4 stroke piston goes...
Down - draws in air/fuel mixture from intake valve
Up - compresses it
Spark ignites
Down - pushed by ignition, power stroke
Up - expell exhaust through exhaust valve

Hence four strokes of the piston for one ignition

2 stroke has oil and gas mixed, no valves, gets ignition every two strokes of the piston...

2 stroke motors are much lighter than their 4 stroke counterparts, have fewer things to break on them, are easier to work on, and create just a bit less than double the power for the same size of piston (displacement, eg "500cc" 2 stroke is as powerful as a "900cc" four stroke). Two stroke you have to shift more as it has a smaller powerband in terms of rpm's it creates good power at. The 4 stroke creates more torque, a lower rpm "grunt" force. They make better power to carry you out of corners and have better "rideability."

2 strokes have more emissions by far (unspent fuel hydrocarbons primarily) and are on their way to being no longer produced for western countries as a result.

Answer 2

The 4 stroke goes 1. suck 2. squeeze 3. bang 4. blow. (intake of air fuel / compression of air fuel / ignition of compressed air fuel / exhaust of burnt air fuel) All this is done between the cylinder head and the top of the piston, (so there is only one chamber where all this happens). Valves in the cylinder head let the fuel mix in, close for compression stroke and firing stroke the open for the exhaust stroke. The 2 stroke combines all of the above into 2 strokes, by using the piston to replace the function of the valves in head of the 4 stroke plus the area under the piston (i.e. the crankcase). So there are two chambers where this happens. There are a number of tubes and holes (called ports) in the cylinder wall all at differnt heights. 1. between the carburettor and the crankcase, 2. between the crankcase and the upper part of the cylinder 3. between the cyclinder and the exhaust pipe. To keep it simple we start from when the engine is first kicked over. When the piston goes up, it opens the port between the carburettor and the crankcase so that fuel/ air is sucked into the crankcase. When the piston goes down it closes the port from the carburettor and forces the mixture through the next port past the top of the piston into the combustion chamber. As the piston continues it closes this port and begins to compress the mixture. ( At the same time the next lot of mixture is being sucked into the crankcase.) This the suck and squeeze both happening at the same time. That is one stroke. When the piston gets to the top of the cylinder the spark plug ignites the fuel which pushes the piston back down the cylinder, as the piston goes down it opens the last port to the exhaust pipe. The shape of the exhaust pipe helps to suck the burnt mixture out, and it is pushed along by the next lot of mixture coming up from the crankcase. This is the bang and blow combined into the 2nd stroke. The whole process is continuous and a little more technical but it should give you the basics.

Answer 3

A 2-stroke engine has a compression stroke and fires every second time the pistons reach TDC (top-dead-center). The 4-stroke engine has a compression stroke also, but only fires every fourth time the pistons reach TDC. 2-stroke engines burn a specific ratio of oil and gasoline, which is mixed (manually or automatically) and put into the fuel tank to provide engine lubrication. Ratios such as 32:1 and 27:1 are common. 4-stroke engines burn gasoline only. Their lubrication is provided by an independent oil system. NOTE: the production of 2-stroke engines is decreasing every year because of technological advances being made in 4-stroke engines.

Answer 4

These are all good answers. I'll add one more thing, though. Most dirt bikes are two stroke - very powerful for short distances, very light and easy to handle. A distinctive ring-ding-ding sound. Most street bikes are four stroke. Vrrrm vrrrrm!!

Answer 5

the question is a bit vague but i guess you wont to know about the pour and relabel
the 2 has moor pour due to the speed the piston travels because there r less parts in the engine but it all sow means that thy wear out quicker ,but thy r essayer to fix and cheaper
the 4 has a little less pour but last longer .and harder to fix and more XE if you wont to go hard and fast go to the 2
if you wont to just cruse go for the 4

Answer 6

in 2 stroke it takes 2 revolution to make 1 cycle whereas in 4 stroke it takes 4 revolution to complete 1 cycle.............

Answer 7

if u r in India, currently only 4 stroke is available;

they give more milage for same power;
& better for preserving environment - air-quality!

if u want more tech. then google it!

so, buy 4 stroke; pollute less; go far in less money;

many-ques!!!

Answer 8

IT PERTAINS TO 4 STROKE =INTAKE COMPRESSION EXPANSION EXAHUST ALL PERTAIN TO HOW MANY STORES THE PISTON DOES TO COMPLETE A CYCLE 2 STROKE =INTAKECOMPRESSION EXPANSIONEXAUST HALF AS MUCH AS THE 4 STROKE FUEL AIR COMESIN IT IS COMPRESSED PLUGS FIRES MIX IT IS EXUASTED

Answer 9

4 stroke engine run on otto cycle
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2 stroke run on carnot cycle
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2 stroke needs more lubrication than 4 stroke
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for same cc 2 stroke gives more power than 4 stroke
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2 stroke engines needs more mantainance than 4 stroke
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want to know more then emailto me im a mechanical engineering student 3rd year