The Great Debate: Two Stroke vs. Four » Page 2 » QUADCRAZY ATV Community Forum

mywifeknowseverythin · 08-25-2007, 09:45 AM

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Because oil is put in the combustion chamber, two stroke engines smoke a lot, which is the reason for the imminent ban on them

If you know how to Mix Properly they dont Smoke much....The Leaner the Meaner

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Although the rebuild is not terribly expensive, it must be done periodically to avoid rebuilding the entire engine.

Again,,If you know how to Run your ride you wont have an Issure....Ive Seen 2 Smokes on thier Stock Piston Running Strong after 20 yrs....

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In order to tap into the power of a two stroke engine, you have to keep the throttle close to wide open to stay in the power band.

Oh my God!!!! This article is Clearly an Attack on the 2 Strokes...Im at a loss for words right now...

DirtDemon · 08-25-2007, 10:51 AM

"In order to tap into the power of a two stroke engine, you have to keep the throttle close to wide open to stay in the power band."

WTF I don't think they would say that again after riding a big bore 2-stroke like a CR500 or KX500.

Sc0tt · 08-27-2007, 01:14 PM

Maybe you guys need to go lobby for us 2-strokers.

admin · 08-29-2007, 07:05 AM

2 Stroke vs. 4 Stroke

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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. In fact they are being banned in 2006. 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.

Each time a new charge of air/fuel is loaded into the combustion chamber, part of it leaks out through the exhaust port. That's why you see a sheen of oil around any two-stroke motor. The leaking hydrocarbons from the fresh fuel combined with the leaking oil is a real mess for the environment.
These disadvantages mean that two-stroke engines are used only in applications where the motor is not used very often and a fantastic power-to-weight ratio is important.

Engine Comparisons

mywifeknowseverythin · 08-31-2007, 11:52 PM

So I take it You (Admin) are for Pro 4 Stroke??????

admin · 09-01-2007, 09:59 AM

No not at all, 2 strokes are more fun in my opinion! Just publishing a part of a description on "How a 2 Stroke Engine Works" from Engine Comparisons for those who do not know the difference between the two in detail, and to add some light on the debate.

This is from the website: HowStuffWorks - Learn how Everything Works!
:smile:

DirtDemon · 09-01-2007, 08:36 PM

2-strokes kick a$$

Sc0tt · 09-04-2007, 04:50 PM

Yeah what he said!!!

BuckBilly · 09-17-2007, 06:58 PM

I have not riden a 2 stoke since 87. A friend had a 250 QuadRacer. WOW that was a blast. If you ever get a chance to ride a 2 stroke , do so! I think the reason they did not try to keep the 2 strokes is because they are to worried about utility sales and not enough about sport quads. Personally I think there should be a quad for everyones needs and what they want. 2 strokes are pushed aside like 5 speeds will be for utility quads. I do not ride sport quads anymore , but the 2 strokes are a rush!! Long live the 2 strokes you guys and gals out there own or own down the road.

yamaha468 · 09-30-2007, 01:30 AM

The main reason for the change is pollution. 2 stroke engines go way back. Alot of diesel engines used to be 2 stroke. There is a plus side to it. This is the reason that 4 strokes have progressed so much in the last couple of years. The atv manufacturers had to come up with 4 stroke engines that would keep up with the power demands that motocross and other types of racing demanded. This wasn't a recent decision. The first I heard about the 2 stroke issue was around 1999. That's why the thumpers started showing up. Look at it this way. If they phased 2 strokes out and the riders had to start riding the 4 strokes that were around in 1998 the riders would have been really upset at the power loss that they would have seen. Not to mention the weight of the motors back then. So they started making motors like the 400ex, the 660raptors and the 450's. They used existing technologies to base these motors off of. For instance, You'll notice that the new motors have oil tanks on them. The reason for the oil tank is because with an oil tank the motor doesn't have to be as big and the less oil you have in the crankcase the less the crank has to move through. This technology has been around for years. Alot of race motors(v-8 motors) use a dry sump motor for the same reasons. So with less oil in the crankcase the cases don't have to be as big which equals less weight. Remember how big the old 350 motors used to be. That was partly because all of the oil was in the cases. But all this doesn't mean that the 2 strokes are gone forever. There are already people making all of the 2 stroke parts that you'll ever need. I like 2 strokes, but I also like the challenge of making the 4 strokes fast. We are catching up. Look at it like this, Take a banshee motor. A banshee motor fires and makes power 2 times per revolution of the crankshaft. A 4 stroke makes power 1 time for every 2 times the crankshaft makes a complete revolution. That's the reason they put out so much power. Now they have people making cases to put a 3rd cylinder on banshees. The 2 strokes are long from being extinct.