MOPED ARMY

In general, the 505D engines come with the square head and all others come with the tapered head. Carb numbers have little to do with the engine itself since carbs can be and are readily exchange at the whim of the owner.

Were I to sell my Sachs in its current condition and insist to the buyer that it is completely stock (IF he was a layman) he would have an excruciating task of finding OEM parts should anything get mussed up. Many of my crucial system components are from different brands. The Sachs I recently rebuilt came with a 10mm square bing in mind, I've replaced it with the 12mm version but it is still classified as a "D" only now the top speed will increase.