[old jupiter]

Excellant! I didn't suppose this site was populated entirely by bark-eaters and CARB bureaucrats, but I'm glad to find you contrarian types!

It certainly is possible to manufacture more fuel-efficient and "clean" 2-strokes with port fuel injection, pressure oiling, computerized ignition getting feedback from various sensors, closer manufacturing tolerances, ceramic-top pistons, and so on.

It isn't likely to happen very often, however, because the Green crowd has cowed the manufacturers and brainwashed politicians by castigating all 2-stroke engines as "filthy" in testimony before Congress and elsewhere. Why this crowd is consulted for this sort of "technical expertise" is a mystery. By and large the Greens were liberal arts majors, have had their noses in books most of their lives, and have never had grease under their nails. They imagine that products on store shelves came to be there by some form of immaculate conception, and have no clue as to what engineers and blue collar skilled tradesmen actually do, and they share this ignorance with our educational, political, and legal establishments. So when they denounce 2-strokes as "filthy," the powers-that-be readily accept it, having no frame of reference by which to judge such "technical" assertions.

Yet even conventional crankcase-oiled 2-strokes like my RD are a whole lot cleaner than the old 2-strokes that made the reputation that stuck. Up to the late '50s, 2-strokes generally used about 16:1 pre-mix ratios, using oil we might now refer to as "bunker C". And since most owners of 2-stroke equipment were as clueless then as now, they would pick up their chainsaw, still half-full of stinky four-month-old fuel, and try to fire it up without vigorously shaking the saw to re-mix the oil that had all settled out of the gas. When the engine finally started, the oil still had only partially re-mixed from all of the shaking of the extended starting proceedure, and the oil-rich mixture would pour out clouds of smoke. Later on, of course, the engine would go oil-lean and maybe stick, which added the the 2-strokes undeserved reputation for reliability. To this day, hardly any homeowner knows the few easy tricks to keeping his weedeater and backpack blower and chainsaw and similar equipment happy, so the "unreliable 2-stroke" nonsense continues. Even guys who should know better . . . decades ago I'd go for a weekend of dirt riding, and when I got out of my tent Sunday morning, I'd go over to my bike and tip it back and forth a bunch of times, with other guys scratching their heads. Of course, that oil was SUPPOSED to stay mixed, but why take a chance?

Anyway, since the old days we have gotten oil that works at 50:1, 80:1, and even thinner, and some of it really does stay mixed pretty well. Result: a lot less smoke. Since the mid-'60s, outboard motors no longer drain excess gas/oil out of the bottom of the crankcase while trolling, but send it back to the carburetor (this change meant that the new motors wouldnt troll as smooth as the old ones, but that was a price worth paying). Unfortunately, the politicians, brainwashed by the Greens, are banning 2-stroke outboards from lakes all over the country. Funny, Kiekhaefer, maker of Mercury outboards since the Forties, had their own private "Lake X" in Florida where they tested engines. In the late Sixties, after they had run hundreds of thousands of gallons of (the old style) pre-mix through hundreds of engines (mostly lacking the crankcase re-cycle circuit) on that small lake, somebody thought to get a lab to test for oil pollution. Next to none was detected; the fractions were light enough to have evaporated. Banning 2-strokes to "save" lakes is like most of what the Green-influenced politicians come up with: High image, low content.

(This wasn't intended as a political editorial except as related to 2-strokes. But lest someone mmisunderstand, please accept a one-paragraph digression because I don't want you to think I scorn all environmentalists. Some are very sharp, have far more tech expertise than I do, and insist on practical results over feel-good band-aid fixes, and they are gradually moving their movement, kicking and screaming, toward a more productive and cooperative attitude. The knee-jerk Green-bashers and deniers on the other side need to be re-programmed in a similar way. And government at all levels needs to wise up (making bio-fuel from corn instead of the many alternatives is a particular example of poorly executing a basically good idea). End digression and beg pardon.)

I'm interested in hearing more about the variable timing system retrofit. My RD400 has what could be called the "First generation" ignition upgrade: a pair of K-Mart coils, and the points-cam reground mostly by hand for more dwell, oh and the plugs gapped to .032-.035". This was a popular fix in the mid-'70s, and gave a real improvement in ignition and plug life, though not as good as the later electronic ignitions, I understand.