Two-stroke emissions not so bad?

[Badjelly]

I got the maths wrong BTW, its only 30 times as much.

Oops, I should have noticed that. (I'd insert an "embarrassed" smiley, but I can't find it.) A factor of 30 is closer to what I've seen from other sources.

There remains the question of how much hydrocarbon emissions matter. I'm not sure about that.

Edit: Actually, we're both still wrong, 7500/300 = 25.

[Badjelly]

Of course it is. Two strokes are never a problem. They're SPECIAL.

Ridden by SPECIAL people?

[Dave_G]

The real issue with a 2 stroke is the un-burnt hydrocarbons, not the burnt ones (i.e. the smoke) as the dangerous stuff is in the particles that are blown out the back end. They tend to over fuel i.e. there more fuel goes in than they can burn, so at the exhaust the level of un-burnt stuff is quite high. In a large way this is just a function of the way a 2 stroke works in that the charge is sucked through to the exhaust can then rammed back by the reflected pulse, only not all of it makes it, hence the emisson issues (and consumption problems).

I, of course prefer to think that its all an evil plot hatched by 4-stroke owners who new they would never be able to compete any other way so they set out to ban them!

[gijoe1313]

Ridden by SPECIAL people?

Ahyuk Momma always done tol'me I wuz always speshul!

I luvs my purty two-stroker smoker I does, she always done me no wrong and is the sunshine in ma' life!

Dem'blimm'n gubbermint types are always angl'n to cheat us simple folk they is!

Well if'n they come fer my Pippi and Daisy, I got a double load of varmint chasers for dem' whee doggy!

[Motu]

There remains the question of how much hydrocarbon emissions matter.

Frankly Badjelly....I don't give a damn.Riding a 2 stroke is worth all the black looks and talking behind my back - riding bikes is all about having fun,and shit...nothing is as much fun as a 2 stroke motorcycle!

[craigs288]

Two strokes are also effectively exempted from the WoF visible smoke test (technically, they must not smoke more than they did when new. But who is going to be able to judge that !)

So when I accidently make a 20:1 premix and look like I'm laying chemtrails through the waitakeres and around west auckland, I'll tell mr policeman that i've always run it at 20:1 and it has smoked like that from day one.
Never had one seize on me yet.

[jcupit69]

It was a shame when the emissions laws stopped most companies from producing the bigger 2 strokes, personally i love them 2 bits

from owning a 4stroke 250 and going back to a 2stroke you can visibly see the amount of beautiful smelling smoke there is come out of the back of the 2stroke (and if your in a closed garage you'll soon realise how much, lol). Also as you have to run alot of them for 5 mins befor you ride anywhere anyway, ur running the engine for longer than you would a 4stroke aswell.

But thanx ixon, nice to no my baby will be safe till the oil runs out

[Ixion]

So when I accidently make a 20:1 premix and look like I'm laying chemtrails through the waitakeres and around west auckland, I'll tell mr policeman that i've always run it at 20:1 and it has smoked like that from day one.
Never had one seize on me yet.

Yep. From the VIR manual

Vehicle with two-stroke engine or
rotary engine.
The smoke produced is not noticeably and signifi cantly more visible than it would have been when the
vehicle was manufactured and supplied with the fuel recommended by the manufacturer (Note 4).

[Motu]

And most 2 strokes will smoke less then when they were new because the oil these days is so much better.When they ran on SAE30 at 16:1 it was a real smoke screen.Same engine at 40:1 or 50:1 on synth will be almost smokeless.

[Coyote]

As I understood it, the production of a vehicle sends out more toxic gas than the vehicle will ever pump out in it's lifetime. Basically making the idea of disposing of an old vehicle for one that emits less toxins ridiculous.

Could relate to 2 stokes. Since they're easier to rebuild an owner may keep it longer.


By the way, would I really help save the planet by getting a scooter?

[Badjelly]

Frankly Badjelly....I don't give a damn.Riding a 2 stroke is worth all the black looks and talking behind my back - riding bikes is all about having fun,and shit...nothing is as much fun as a 2 stroke motorcycle!

One person who doesn't give a damn, no problem. A million people who don't give a damn and you get serious air pollution. Some people do give a damn about that.

[Badjelly]

As I understood it, the production of a vehicle sends out more toxic gas than the vehicle will ever pump out in it's lifetime. Basically making the idea of disposing of an old vehicle for one that emits less toxins ridiculous.

Got anything to back that up? I doubt it, myself, but I don't have anything to back that up right now.

There's toxins and there's toxins. The specific toxin (well, class of chemicals, some of which may be toxic) that two-strokes put out in large quantities is hydrocarbons from the unburned (or partially burned) fuel and oil. I don't think vehicle manufacture does result in any significant amount of hydrocarbons in the air.

[Badjelly]

And most 2 strokes will smoke less then when they were new because the oil these days is so much better.When they ran on SAE30 at 16:1 it was a real smoke screen.Same engine at 40:1 or 50:1 on synth will be almost smokeless.

Good point. I'd like to learn more about the factors effecting 2-stroke emissions. I think the unburnt oil ends up as smoke, but there's also quite a lot of unburnt fuel that is invisible. One of the references I found yesterday said that 30% of the fuel that goes into a 2-stroke comes out unburnt. That's mind-boggling! (But I need to find a better source before I'll believe that number.)

[Badjelly]

It was a shame when the emissions laws stopped most companies from producing the bigger 2 strokes, personally i love them 2 bits

Was it really the emissions laws that stopped most companies from producing the bigger 2 strokes? (I'm thinking of the the time when mainstream bikes like Suzuki T500, GT550, GT750, Kwaka H1, H2 were two-stroke, not so much the later, sharper vehicles like Yamaha RD350LC, Suzuki RG250.) I think it was more that the customers didn't want them. But I must admit I don't really know.

I quite liked my Suzuki GT250K, though I did get embarrassed when I opened the throttle and it left a smoke trail you could walk on!

[McJim]

My dad bought a 2 stroke car in 1973. Even then he told me never to stand behind it when the engine was running otherwise I would stand a good chance of death by toxic inhalation. He used to carry huge quantities of 2T oil around. 993cc 2T engine.