2007-03-06 21:36:38 · 11 answers · asked by ajay c 1 in Cars & Transportation ➔ Maintenance & Repairs
The principal reason two-strokes are not used in road-going motorcycles any longer is because they pollute heavily. However, the Japanese firms are working on coming up with a cleaner-burning two-stroke, so perhaps we'll see them again in the future.
2007-03-08 11:23:57 · answer #1 · answered by katbyrd41 7 · 1⤊ 0⤋
Snowmobiles still use 2 strokes, and in the last few years they have become very dependable as well as cleaner due to tighter emissions standards set by the government. They also use oil injection which eleminates manually mixing the oil and gas by hand.
Snowmobiles also offer EFI or throttle body injection, fuel injection, on 2 -stroke engines. 2-Strokes generally rev quicker and have more top-end power where as 4-strokes generally offer low-end power for stronger "take offs". Although, two-stroke engines don't live as long as four-stroke engines due to lack of a dedicated lubrication system which means that the parts of a two-stroke engine wear-out faster.
But the lighter weight of 2-stroke engines makes it a better choice for smaller powered vehicles, i.e. snowmobiles, dirt bikes, ATV's.
2007-03-07 00:04:25 · answer #2 · answered by jmwillix 1 · 0⤊ 0⤋
The main reason is that they pollute more because they have twice as many power strokes and also burn oil with the gas. They are also a lot less reliable. Two stroke dirt bikes usually need a top end rebuild every 50 or so hours.
2007-03-06 21:45:50 · answer #3 · answered by Tim H 5 · 1⤊ 0⤋
Mainly because of inefficiency. A two-stroke engine has no fuel or exhaust valves. When the piston down-strokes, fuel comes in as the exhaust is expelled. This means a good part of the fuel charge goes with the exhaust meaning poor fuel economy. Hope that answers you question.
2007-03-06 21:44:23 · answer #4 · answered by rustynail_00 1 · 0⤊ 0⤋
For any 2 stroke engine the main drawbacks are:
one exhaust per one revolution of the drive, while in 4 stroke engines one exhaust is per 2 revolutions. So the pollution becomes more.
At the same time it needs one injection per one revolution. So fuel consumptionwiae also 4 stroke wins the race.
The advantage of using a 2 stroke engine rather than a 4 stroke engine is the power,
it means, the two stroke vehicle gets one power stroke per one revolution. In case of 4 stroke it takes 2 revolutions to give a power stroke. So the two stroke engine pick-up more comred to 4 stroke engine.
2007-03-07 22:04:19 · answer #5 · answered by saba27win 2 · 1⤊ 0⤋
2 stroke engines have a good up power range, but they degrade after heating up. There's also the hassle of mixing in the oil. There still used for lawn mowers, chain saws, etc...
If you're asking about motorcycles, it's because the tree huggers don't like the emissions.
2007-03-06 21:50:22 · answer #6 · answered by drivingdog18 4 · 0⤊ 0⤋
The Efficiency of the Two stroke engine is poor. Emission let by the Two stroke engine is on the higher side and it is not capable of meeting more than Euro II norms.
2007-03-08 18:12:14 · answer #7 · answered by kirushnan 1 · 0⤊ 0⤋
Two-stroke engines are being phased out for environmental reason. They create more pollution than a four stroke because they burn oil as a normal part of their operation.
2007-03-07 03:38:43 · answer #8 · answered by ? 4 · 0⤊ 0⤋
Thank the good old EPA because they burn fuel and oil together they put out more pollution if improperly mixed. Also some 2 cycles do have valves ever hear of Detroit diesel?
2007-03-07 05:29:00 · answer #9 · answered by ctlyle43 3 · 0⤊ 0⤋
2stoke engine has a good pick up but due to its sound nonsmoothness,less mileage, inefficency and less saftey at high speeds has made it unusable were all these are achieved in a 4stroke engine
2007-03-07 17:16:48 · answer #10 · answered by Anonymous · 0⤊ 0⤋