Scooterotica

i have always put the brass exhaust nuts on with the round end to the bottom (best way i can describe it) but have recently seen pictures with the nuts the other way . which is correct ?

I always put the round bit next to the washer but I did read somewhere that they should go the other way. I can't see that personally, why design it like it is if the round part has no purpose, which it won't have if fitted flat side down.

corrado wrote: why design it like it is if the round part has no purpose,

Easy.. less grip for your spanner in an awkward place. More chance of slipping and rounding off the edges.

My belife is that the flat part works like a crush washer deforming when you tighten them. thats why they only work once.

I got a set of long ones from Corrado here (thanks buddy!), that you can tie off.

Unfortunatly, they dont fit on my MB clubman, or Fat mamba because the u-bend it to tight against the engine.

never tried to screw them on with round part towards the barrel but wondering now if the thread is tighter in this part of nut (bit like a nyloc) and so round bit down would be correct. Although the other way would maybe make it easier to tighten with spanner.

Fux is correct. The 'round bit' compresses when tightened up against the bottom of the barrel. I believe that's why they are also made from brass to make them softer. They are supposed to be changed when taken off. For reference I believe this is stated in the original Lambretta workshop manual.