Thanks for the nice illustration, interesting to see! Somebody definitely removed the spiral part on mine. I installed the outlet pipe with some sound dampening around it as you suggested and from what my sound level meter says I'm actually within tolerance, so I should hopefully be fine. Can't wait to drive her on the road! Wish you all the best!

Hey Dave, Thanks for your reply. The allowed noise level depends on the vehicles age. For the DT360 81dB are allowed at 4150RPM while stationary and 86dB during a low speed drive by, that’s what the original „ABE“ (General operating permit) from 1973 says. It will also be measured according to the exact procedure from back then, but the TÜV engineer still has to research the procedure. From what I could find I actually seem to have a tolerance of 26dB when measured with the new procedure, since back then they measured from around 7m (23ft) away, now it’s only half a meter (1.6ft) but at a 45° angle to the exhaust, so I‘m probably already good with the setup I have. Anyhow I‘m interested to see how the original muffler was designed, on longer rides the bike is pretty loud even for someone who enjoys the sound 😆. Kind regards Leon

Hey Dave, thanks for the quick explanation, that helped me a lot already. I was wondering about the cross hatches as well, never seen it not being at an angle before. I‘ll talk to the local engine guy to get the cylinder and piston measurements. If I got your explanation right, recreating the correct cross hatches and replacing the piston rings might be an alternative as well, depending on the current piston clearance/wear right? I would like to avoid boring the cylinder too early, to have fun with the bike as long as possible, since I don’t know how long it‘s going to take to get a decent replacement cylinder to Germany. Maybe I‘m a bit paranoid in that case… Do you have the rings in all sizes as well?

If it wasn't over 4000 miles away it would already be standing in my garage... hurts a bit to see what kind of great offers you guys get in the us😖.

Hello Devin, Thanks a lot, with the information you gave registration shouldn't be a problem at all anymore! Best greetings from Germany