You guy's make me sick!

THEY DO NOT BLOW UP MORE OFTEN!!!!!!!

with proper maintenance and care, they'll last every bit as long as a 4 stroke, especially those H.P. thumpers you see today.

Sure, turn an idiot loose that does nothing but beat the crap out of things, and see how long ANYTHING will last....



'stepping off soapbox'......

 

LOL, this thread is funny[img]i/expressions/face-icon-small-smile.gif[/img]

 

strongtyryfz nailed it!

 

lol, not really... Sorry, I didnt have time to make a "real" reply at the time.

2 stroke motors do have valves in a way actually. Its called a "reed valvle." I believe it works kinda like a flap... not really sure exactly on that part of the engine.

The reason 2 stroke pipes have a bulge in them is because, as similarly stated before, it creates back-pressure which pushes the fuel that seeps out of the cylinder back inside so the spark plug can blow it up. Correct me if I'm wrong but the reason 2 strokes have such a noticeable power band is because when your at the right RPM thats when the "best" back-pressure is made and the most fuel can be burnt... It works kinda with the same priciple as a turbo... but not. I have a really good animated GIF that shows a 2 stroke engine at work that you might be interested. PM me if you want it. Its actually pretty cool.

 

The reed valve works basically the same way / reason the intake valve on a 4 stroke, it lets air in but after ignition of the fuel mixture it prevents the compression / pressure from going back into the carb.
http://science.howstuffworks.com/two-stroke5.htm

 

I took this off the How stuff works site.

Disadvantages of the Two-stroke
You can now see that two-stroke engines have two important advantages over four-stroke engines:

They are simpler and lighter, and they produce about twice as much power.

So why do cars and trucks use four-stroke engines? There are four main reasons:

Two-stroke engines don't last nearly as long as four-stroke engines. The lack of a dedicated lubrication system means that the parts of a two-stroke engine wear a lot faster.

Two-stroke oil is expensive, and you need about 4 ounces of it per gallon of gas. You would burn about a gallon of oil every 1,000 miles if you used a two-stroke engine in a car.

Two-stroke engines do not use fuel efficiently, so you would get fewer miles per gallon.

Two-stroke engines produce a lot of pollution -- so much, in fact, that it is likely that you won't see them around too much longer.
The pollution comes from two sources. The first is the combustion of the oil. The oil makes all two-stroke engines smoky to some extent, and a badly worn two-stroke engine can emit huge clouds of oily smoke. The second reason is less obvious but can be seen in the following figure:

I guess I can't say they blow up more often. All of my yard equipment is 2 stroke. Lawnboy mower, Toro snow thrower, chain saw, leaf blower, and weed wacker. I've never had a problem with any of them and my mower is 25 years old. But put this equipment in the hands of my wife or someone else and it is only a matter of time before they add regular gas or give them the improper mix.

 

amen dune addict, my 1993 cr 250 is on its original bore with 185 lbs of compresion,no signs of slowing. I WOULD ACTUALY SAY the new 450's wouldnt last as long as most 2 strokes,because they are all friggin modded out to the max even in stock condition,wich is what you have to do to make a 4 stroke as fast as a 2 stroke. As far as wich is faster,it takes 450 4 stroke cc's to equal 250 2 stroke cc's a 450 2 stroke would absolutely murder the crap out of a 450 4 stroke,if they were both race engines

 

The fat pipes are there for pulse wave tuning to be more correct. When a two stroke is in it's powerband some of the incoming fuel charge exits the exhaust port and then is forced back into the cylinder before the piston closes the exhaust port because of the pulse wave. This is why a two-stroke can exceed 100% volumetric effeceincy. The pipe design has a major influence on the power characteristics of a two-stroke.

Why do they blow up more? All kinds of reasons but most are user error. A two-stroke is far more sensitive to it's jetting/tune/weather conditions/oil-gas ratio.

 

Lets put it this way:

4 stroke is like an old school big V8 has power all the way through.

2 stroke is like a new school turbo 4 cylinder car that just hits that power band hard as hell!

I have my Z then I have an 80 cc shifter kart. I love the kart but I have to rebuild the top end on that about every other weekend I go out. I think that is more because of the "race" type motor that is in it but I couldn't afford that if I had to rebuild for a banshee that often or any other 2 stroke. It is expensive enough to rac ethe kart!

I love both really I would love to have a 2 stroke because of the utter quickness but with the 4 strokes they are starting to produce now-a-days I don't know if it is worth it. I love the Z!!!

 

LOL!!!!! Dude, you might want to try mixing a little oil with your fuel...[img]i/expressions/face-icon-small-confused.gif[/img]