I was up at the local boat dealer and was told that the engine mfg ( Yamaha outboards to be exact ) are going back to 2 stroke models. They have improved the emissions to where the 2 strokes are better than the 4 strokes. Has anybody else heard this ? If this is true we can only hope that it moves to the ATV industry.

 

Yes I have heard the technology has been around for along time...but 4-strokes make manufac. more money...

 

Polaris and other manufacturers have been consistently working on 2 stroke emissions especially in the snowmobile market and have made some great strides. However, they are also heavily invested in 4 strokes for the atv segment and I do not think you will see 2 strokes replacing the 4 strokes but if the emissions issue is resolved I think the 2 strokes will remain or increase in the sportquad portion.

 

if they have had the technology to make thier 2 strokes meet the epa's guide lines i wouldnt think they would have wasted all the money making 4 stroke sleds which are very heavy and dogs. just my guess.

 

They do have the technology......Honda developed a clean burning 2-stroke many years ago

 

Because I can't seem to find the info on the honda I posted B4....here is a totally diffeant company...dodge

www.allpar.com/neon/stroke.html




Information from Automotive Industries

Years ago, when the Neon was first being designed, Chrysler said it would have a revolutionary new two-stroke engine. What happened to it?

Unlike the Orbital (for the Ford Fiesta) dry-sump, roller-bearing, internally-scavenged design, the Neon was to get a wet-sump, externally scavenged engine with direct injection. The engine had no head gasket, with the head and cylinder block cast in a single piece. The fuel injection was to be liquid and direct-injected at 1,000 psi.

Chrysler tested its 1.17 liter Phase 2 engines for 100,000 miles, then started to test Phase 3 engines (with 1.5 liters). That was the design to end up in the 1997 Neon - but it clearly did not! Reliability does not seem to have been the problem, because it was supposed to be a durable design. Nor was performance a real problem: Automotive Industries' test drive showed the 1.5-liter-equipped Dodge Shadow to have strong performance and smooth, quiet running.

In addition to being larger, the Phase 3 engines had a balance shaft rotating at the speed of the crankshaft (unlike the 2.5 liter 4s, which rotate at twice the speed). The engine had external exhaust gas recirculation (EGR) and two spark plugs per cylinder. Chrsler's new engines were designed by a 20-person team (in a joint venture with Mercury Marine), with the goal of selling 25,000 North American 2-stroke Neons. By contrast, Orbital could sell 100,000 engines to Ford, Fiat, GM, and Volkswagen.

The problem in the US, according to members of the two companies, is the reliance on catalyst technologies by the EPA. Specific technologies for on-board diagnostics which may not be completely needed are required by the EPA. The two-stroke engine has extremely low CO emissions (even when cold), low NOx, no catalyst, but also no O2 sensors - which are required by law. NOx emissions actually go down with age.

That may not be the reason you haven't seen two-stroke engines yet. It's quite possible they just have not yet been able to perfect them yet - or that they have decided to use them outside the US for the moment. Or they have encountered machining or other production problems. Wouldn't it be nice for them to let us know?

 

Having the technology is one thing, and clean 2 strokes are there or nearly there from what I understand, getting the certs from the EPA and CARB are another as well as making them affordable to the public. I agree with you Stendori the 4 stroke sleds that are on the market while reasonably powerful are heavy and weight is far more a premium in snowmobiles than in atvs, watercraft or cars. Also, due to the new restrictions for watercraft i.e Lake Tahoe for instance outlawed 2 strokes with no warning practically, the manuf had to throw their resources to 4 stroke tech at the expense of perfecting the 2 stroke clean burn which we are just seeing now (Polaris clean burn 600 and 700). The MX and sportquad market is more tuned to 2 strokes even with the advances in small 4 stroke motorcycles and clean burn will find its way back once the idiots at EPA and CARB get educated.

 

that is old news,we all known the future of clean burning engine is 2 stroke DFI,even ford and gm are testing some
motor with 2 stroke injection trough them to past emissions laws and lowering the cost as much possible for warranty issues ,,i guess we just have to wait maybe 4-5 years again and they will appear at a dealer near you...

 

EVERYBODY knows this?

 

Two stroke cars? Could you imagine the blue haze covering every city. I know the scientifics about emissions are being figured out, but what about the oil burning? When our snowmobile club has a big get together at the lake, after an hour or so there is a blue smog of exhaust hovering over the lake, i can only imagine how muh goes into the water from boats/pwc's. It is the visible exhaust that the environmental people will see as the threat.