Moped Army

Never to my complete satisfaction.

I don't think you'll need to braze it.

Look on the top of the clamp on the carburetor. Mikunis should have a small lip at the end of the pincer part of the clamp - you can see that the gap between the pincers is partially bridged by a short aluminum spur (perpendicular to the attachment axis - pointing down the intake).

If you grind off that lip, the clamp can grab much more tightly - you get perhaps an extra millimeter of movement.

So, I suggest that you grind off the lip (a dremel cut-off wheel fits about perfectly), and try this again. If it doesn't attach to your satisfaction afterwards, you can still use your improved clamp to attach the carb to an aluminum tube, and then pull the rubber hose trick (the rubber hopefully absorbing some of the vibration that would otherwise rattle loose your carb).

+++

I never understood this lip - it looks almost as though it's meant to help seal the attachment point, but there's still a gap between the clamp and carb body that is WAY bigger than this tiny crack could ever be.

It's just an extra bit of finnickyness to grind off. I've done this on Mikuni and Dellorto carburetors many times to attach them to things for which they weren't intended.