- The Washington Times - Friday, February 23, 2001

The Yamaha RD400 was an idiosyncratic end of era. A two-stroke motorcycle that not only enjoyed cultish popularity years after two-strokes were supposed to be dead, but readily challenged the four-stroke motorcycles that were said to bring its demise.

"It was a giant killer," says Eric Wallgren, mechanic and owner of a 1979 RD400 Daytona Special. The RD350, built first in 1973, then the RD400, which followed in 1976, were wicked fast and nimble. On the street and on the track, the 350 cubic centimeter (cc) then 400 cc bikes left larger displacement bikes in the dust.

The key to the bikes' success was a one-way reed valve between carburetor and crankcase. The valve prevented blowback from the crankcase and allowed greater compression, and thus more power, particularly at the low and medium range of the engine's revolutions. The 1979 model added still further compression by lowering the exhaust port.

Still, more-stringent emissions standards would have doomed the bike in 1978 were it not for another ingenious device.

Two-stroke engines tend to pollute, particularly when the throttle is off, by exhausting unburned fuel and oil into the air.

To combat the problem, Yamaha installed a butterfly valve in the exhaust manifold that essentially shut off air flow through the engine when the throttle was off.

Mr. Wallgren's RD400 is a mint condition, nearly stock version of the Daytona Special, a compact machine made even more so with the lowered aftermarket handlebars he has added.

Riding in a full crouch it seems as if your helmet, not the headlight, is the bike's leading edge.

The double-cradle framed bike weighs in at a sprightly 388 pounds, pulls a peaky 34 horsepower at the rear wheel, and tops out through six gears at about 110 miles per hour.

A snub-nosed wheel base of 52.5 inches gives it agility. It also makes the bike insanely easy to wheelie.

Most discussions of old bikes remember 20 years is the equivalent of 40 in automobile age include a substantial caveat. As in, it rides well for a bike its age.

Well, the RD400 rides well. Period.

Are the modern bikes better? Yes.

But a stint down a local winding road made me see not shortcomings, but possibilities. And while the suspension was a little spongy I would love to try one on the race track.

Okay, the engine did tend to porpoise if you tried to hold it steady between 4,000 rpm and 5,000 rpm. But, I still want to take it on the track.

Ironically, Mr. Wallgren didn't even want the bike.

He is a talented mechanic by vocation and avocation. When he is not working on his own bikes, he is often fixing others. And because he works on bikes, people often offer him bikes, sometimes as barter and generally at a discount.

About 14 years ago, he had been working on a BMW motorcycle for a man who ran out of cash before the BMW ran out of problems. The man offered to give Mr. Wallgren the RD400 in trade.

"Absolutely not, I don t want any more RDs," said Mr. Wallgren, who has had five RDs and three RD Daytona Specials over the years.

Still, the next morning, the bike just "showed up outside his house like an abandoned baby in a basket."

The bike needed some work, so he cobbled together an engine from it and the two other Daytona Specials he had in the garage.

It was the second time the engine seized that Mr. Wallgren decided a more complete fix need to be undertaken.

It was not that the engine was unreliable. Mr. Wallgren says that for more than a decade it has been a one-kick-and-it-starts kind of a bike.

But riding routinely at 100 mph pushed small imperfections to the point of failing leaks. Leaks meant one of the two cylinders ran lean and therefore hot. And that left Mr. Wallgren with a seized piston at 100 mph on the Beltway. Twice.

So, he replaced everything. Pistons, gaskets and bearings. Forest Kearns, something of a local legend as a two-stroke rider and as a machinist, welded the crank.

The bike has been unstoppable ever since, Mr. Wallgren said.

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