The problem ... Darda from Germany no longer exists. The replicas come from the Far East ... Those who think that one can easily reorder an engine will possibly be disappointed. The replicas are not necessarily getting the speed and power of the old engines in the then new state or / and - much they Worse grind because of large component tolerances when mounted on the vehicle body.
Unfortunately, one is in front of it also not be protected if the new mini-engine is professionally packaged in blister ... Last time I ordered so five engines that did not work all (!) Properly. Thanks to Amazon, I could convert the particles poblemlos again, but what to do?
First of all, throw away any old motors! In the "network" for example are on Youtube a number of small movies available that can help to revitalize probably 50% of the old engines again. And even if a part of the engine is missing or defective.
The second way I find very sympathetic: just go once again to the well-stocked toy stores locally. This like taking care of the problem and may help while sampling locally.
The third option consists of buying a complete new vehicle. It costs a little more, but strangely enough this there built engines run properly. Without having tried them, but I would no longer buy individual spare engines.