Carl Spaatz and Ira Eakin-the two legendary leaders of U.S. air power in World War II–just got it all wrong when they decided to bomb the German ball bearing factories at Schweinfurt in 1943. What they should have been bombing is the factories that make those little skinny spring washers that the Germans cant seem to build so much as a toy wagon without using by the gross. The war would have ended a year earlier.I was reminded of this today when my correspondent Stan Fetter wrote this note about his experiences in repairing a Thielert diesels all-critical clutch: There are a bunch of spacers in there, and if any of that stuff comes apart the whole thing has to go back to the factory…Had a new one on the bench and the tool guy picked it up and moved it, and stuff went everywhere.Been there…and the t-shirt is now a shop rag. I have a couple of motorcycles, a BMW and a Honda. To service the fuel pump and filter on the BMW, you need a pair of hemostats-no kidding, thats what the shop manual says-to squeeze off the fuel hoses while you worry the thing out the side of the fuel tank, being careful not to trash the $400 fuel gauge sender. And dont forget the special clamps which you must replace. On the Honda, the same assembly drops out of the bottom of the tank in five minutes. Buy the clamps at NAPA.This aside is central to the problems Thielert is having with its aerodiesel. The thing requires a lot of wrenching-replacement of the gearbox and clutch assemblies, fuel pumps, alternators and so on. And its not simple wrenching, thanks to the German penchant for using two spacers where one will do, a spring hidden in an invisible blind hole that rockets across the shop and careens off the bench grinder and disappears before you even knew it was there. And great clouds of those damn flat washers which are always left over after youve reassembled the part without the missing spring because theyre out of stock and the parts guy says they leave them out, too.Which brings me to this: Whats needed here is for Honda to stop screwing around with four-cylinder gasoline engines and to get busy with aerodiesel. For reasons related to culture, economics and predisposition, the Japanese havent been big on diesel engines for cars. In fact, Honda is expected to launch its first next year. By dint of long experience-the Germans own the diesel car market-the Germans have diesel pretty well figured out. It will be daunting for others to catch up. But to a degree, the Germans are victims of their own success when it comes to building things that are easily maintainable. They tend toward in-the-box thinking with regard to repairing things. The Japanese have proven to be better at this, at least in cars and motorcycles. It would be intriguing to see their version of a practical aerodiesel.