Total Motorcycle Community Forums

what is the difference between the two types of strokes in motors?
motor powerful? quicker?

and reading a magazine I came across two things...
people say top end power... what exactly does that mean?
and...
in one of my recent post a guy said DUMPING THE CLUTCH, what exactly does that mean...

thanks alot!

Four Stroke Engine:



Two Stroke Engine:



As you can see the four stroke engine fires on every fourth stroke while a two stroke engine does so on the second stroke. This means that a two stroke engine is able to make more power at any given engine capacity than a four stroke engine. The drawbacks to this power are poor fuel economy, dirty emissions, and high maintenance. Two stroke motors wear out faster than a comparable four stroke motor.

Two strokes are really a thing of the past and for and they arent the best way to go for road bikes. The cost of running one is two high and the power delivery is very unpredictable.

Dumping the clutch refers to just letting go of the clutch instead of easing off of it. Used for wheelies, drag racing and such. It's very hard on the clutch though.
_________________
24 Forum

Wow, a 2-stroke with a tulip intake valve! I've never seen that before. Very interesting concept.

Forget 2-strokes. They are dinosaurs. 2-stokes are cheap, light, and powerful for their cost and weight. They are also very easy to work on. Just the ticket for up-and-coming 3rd-world schoolboys with ambition. 2-strokes are not compatible with modern emissions and fuel efficiency concerns because they burn a lot of gas for the power they make, and they STINK!

qwerty wrote:Wow, a 2-stroke with a tulip intake valve! I've never seen that before. Very interesting concept.

Forget 2-strokes. They are dinosaurs. 2-stokes are cheap, light, and powerful for their cost and weight. They are also very easy to work on. Just the ticket for up-and-coming 3rd-world schoolboys with ambition. 2-strokes are not compatible with modern emissions and fuel efficiency concerns because they burn a lot of gas for the power they make, and they STINK!

The first successful two-stroke engine was developed and built the same year as the otto cycle four-stroke engine. So really they are the same age, unless you take into consideration that the first patented internal combustion reciprocating gasoline engine, four stroke, was registered I think 16 years before one was ever built.

Yes, two strokes have not met the ever tightening emissions, but research from some companies have taken great leaps forward in both emissions and fuel economy. If I recall one company has taken some ideas from diesel technology. Ill try and see if I can dig up a link to the company I have in mind which has done this, when I get home.

2-strokes are better in my opinion. Why? They weigh less, produce WAY more HP for the size, and if they had seen the kind of development in the last two decades that 4 strokes had they would be just as clean burning.

Yes, they are less fuel efficient (now) and yes they burn oil (now) and yes they might pollute more into the air (now). But, you have less complex, more power, lighter weight, and easier to maintain.

Like I said above, in the last 20 to 30 years 4strokes have seen a tremendous amount of development, and are just now starting to see the level of power production that a two stroke is capable of, and they weigh more.

When you start looking at dirtbike racing they run 125cc 2strokes against 250-300cc 4-strokes. Twenty year old tech with 1/2 the displacement and the same power...

Give me a 600cc inline 4 - 2stroke bike any day. I'll molest the "poo poo" outta that.

First the graphics and your information are right on. Second for many years the four stroke was not as powerfull as the two stroke. The fact is that dirt bikes, road bikes, lawn mowers, outboard motors and more are all four strokes. And the power advantage and response no longer belongs to two strokes except in little tiny engines.

Gentlemen, start your weed wackers.

Two stroke can be more expensive to run, due to higher fuel consump. oil costs etc. BUT they are much much easier and often cheaper to repair. Ever tried replacing the piston rings on a 4 stroke half way through france? I did so with my 2 stroke, took half an hour by the roadside.

Then again 4 strokes are easier to live with in the long run, smoother quiter, less stinky. It takes some guts to drive a 2 stroke in town, as people will constantly be complaining about the clouds of blue smoke belching out of exhaust pipes that like to leak unburnt oil all over the road.

That said, there is nothing as grin indicucing IMHO as a two stroke thats hit its power band and starts howling while trying to pull your arms out of their sockets.

snwflk303 wrote: And the power advantage and response no longer belongs to two strokes except in little tiny engines.

Like, MOTORCYCLE engines!

2-strokes that make power are smelly, inefficient handgrenades. If it was cost effective to sell 2-strokes that were competitive with 4-strokes, and met efficiency standards, somebody would be selling them. If you would have had a 4-stroke on your ride across Europe, you probably wouldn't have needed rings in the middle of your ride.