Even if you don't speak German, this video is pretty self-explanatory.
Jochen Sommer has been using 462cc Hatz deisels in his Bullet-based diesel bikes for some time, it would be interesting to see one of his tested against one of Henry Price's diesel conversions (which is what happened to my old Electra-X).
More recently Herr Sommer has been fitting 516cc engines, and he's somehow got them passed for Euro4, presumably NOT the way Volkswagen did with US emissions regs! ABS is on the cards for full Euro4 compliance in 2019. This was lifted from the web site
http://www.motorradmanufaktur.de/index.php?main=home (via Google translate, add your own German accent).
"The media, the fumes and no end? 12.03.2018 / 19:46
The media and environmental organizations have discovered the diesel engine as the culprit of all nitrogen oxide and air pollution problems. Everything in the car has a lower EURO homologation than EURO 6 is considered polluters or stinkers.
At this point we do not want to take part in this technically most hair-raising discussion. Of course, many people interested in motorcycling are currently asking about the pollutant emission of our diesel motorcycle.
For motorcycles, the highest homologation level at the moment is the EURO 4 class. As already described, this emission class will be binding for all motorcycle manufacturers from 1.1.2019.
The SOMMER Diesel 516cm³ motorcycle from current production has already been in compliance with this emission standard since 2016. By the way, as a customer, you are assured that we always produce in line with the times and current standards in our production. Incidentally, the only diesel motorcycle manufacturer in the world.
And the whole thing with two liters of fuel per 100 km (265 mpg). Also unique in the world... (= 265mpg)
Registration information for the year 2018 26.01.2018 / 12:26
The registration year 2018 is formally a transitional year from the admission regulation EURO 3 to EURO 4. All manufacturers are allowed to sell a limited contingent of EURO 3 motorcycles this year, but of course also offer EURO 4 models. All EURO 4 vehicles over 125 cc must have ABS (antilock brake system).
For your Sommer motorcycle this means that this year you can still purchase and allow a vehicle completely free of electronics without ABS. The vehicle already has the EURO 4 tested 516 cm³ HATZ engine but is still formally a EURO 3 vehicle without ABS. The ABS equipped summer diesel motorcycle will be offered only from January 2019.
There is no tax differentiation for motorcycle emission classes in Germany. This means that all vehicles are valued according to the same tax rate.
The above regulation also applies to the entire EU foreign countries. However, only the 462 cc engine can be registered here in 2018."
Still not my cup of derv, but I'd be interested to have a brief ride on a diesel Bullet.
A.