Clearing the Air

CLEARING THE AIR

ROUNDUP

Emission-controlled motorcycles have become a fact of motorcycling life, though mostly a sad fact. Since federal emission laws were enacted we've encountered numerous rideability problems with emission controlled bikes.

So it was with concern, skepticism and a little disgust that, we heard California planned to go ahead with even more stringent emission rules for future motorcycles. The standards proposed, according to motorcycle manufacturers, would require motorcycles to be equipped with catalytic converters, among other pieces. And because California is such a large segment of the motorcycle consuming public, it would even be possible that the made-for-California bikes would be sold to the rest of the country. Obviously cause for Concern.

After sitting through meetings with the California Air Resources Board recently, though, there is a tiny bit of hope.

First, a little background information is in order.

California, like lots of other places around the country, has a smog problem and may never be able to reach federal clean air standards for much of the state. So in 1975, after a dozen years of controlling what comes out of automobile tailpipes the CARB (what an appropriate acronym) announced its first smog stan-

dards that would eventually lower the maximum amount of hydrocarbons put out by a motorcycle to 1 gram in a kilometer of riding. That nurnber’s important.

Shortly after California set its standard, the federal EPA got into the act and laid down a bunch of other numbers, eventually ending up at the 1980 and future federal emission standards. The numbers need some explanation, though, because they wouldn’t make sense otherwise.

Motorcycles, prior to emission standards, were jetted rich and there were lots of two-stroke bikes on the roads. Rich jetting and two-strokes make for lots of hydrocarbons (essentially unburned fuel) and carbon monoxide (a leftover from incomplete combustion) but also make for very low oxides of nitrogen (NOx). The

NOx is created by high combustion tem-

peratures, which is why two-strokes and four-strokes with rich jetting are low on NOx readings.

So if you designed an engine to run cleaner by putting out less HC and CO, it would end up putting out more NOx. Add to that a little smog theory: the stuffs made by mixing HC and NOx and baking under sunlight.

Now then. Because pre-controlled motorcycles were running rich there was essentially no NOx being emitted so the

federal standards only controlled HC and CO. And the HC standard wasn’t all that tight: virtually any properly tuned fourstroke engine would meet the HC standard without modification. To meet the CO standard the carburetion was leaned out by most companies and that’s what caused the rideability problems we’ve been putting up with.

Let’s go back to California now. The CO isn’t a problem in California because it doesn’t make smog. But in making sure all production bikes would meet the CO standard, the bike makers also reduced the HC output well below the 5 g/km federal standard. Many bikes tested almost meet the 1 g/km future California standard, though in order to allow for production variances the manufacturers expect the bikes will have to be designed for an HC output of around 0.6 g/km and that will require catalytic converters for large motorcycles.

That’s where the CARB comes in again. During the all-day hearing it became clear that all the major manufacturers have been experimenting with catalytic converters and thermal reactors and fuel injection and air pumps and all sorts of smog equipment. And they are ready to make motorcycles with this stuff added

But motorcyclists (that’s you and us), the board feels, won’t accept a loss of performance without tampering with our bikes. Probably right about that, too. And because catalytic converters aren’t famous for improving performance, the board was afraid we’d take them off bikes so equipped and the end result would be more smog, not less.

So the CARB delayed the proposed 1 g/km standard two years for large bikes and instead imposed a limit of 2.5 g/km which most all motorcycles can meet without further modification.

The decision is important to motorcyclists outside California because, as the CARB staff pointed out, future federal smog standards will likely be based on what California adopts.

Fortunately, in the words of one member of the state board, “Whatever we do, we cannot affect the performance of motorcycles because the motorcycle buyer won’t accept it.”

We may yet be faced with catalytic converters on motorcycles, but as long as motorcyclists don’t give up, continue to expect good performance, and stay politically active, the end is not in sight.