Modern Vespa

These are the torque specs I found for Primavera https://members.modernvespa.net/marubadu/uploads/torque_specs_12348.pdf

and I need help translating:
Exhaust system to port nut 12 to 16 ft lbs
Exhaust system to crankcase bolt 25 to 35 ft lbs

Is the first (port nut) to the cylinder? -- that's what I'm looking for. But what's the second one?

Technique question: the exhaust elbow bends around one of the studs at the cylinder so there's no way to get a socket on it. Do you just torque this by feel or do you have some way of measuring it?

Do the little ones on the cylinder by hand. Goop all the gaskets on that 90* bend.
Wrist tight.

The big bolt on the can in front of the tire tighten to elbow tight.

correct, the first is the pipe to the cylinder connection. depending on the size of the stud or bolts, I'd err toward the smaller end of that scale. also, hi-temp sealant on the flanges.

same for the elbow, shoot more toward 10~12 than 15ish and just do up the one you can't reach with a wrench. same, here with the sealant.

the second is the pipe mount bracket to the swing arm.

of critical importance: make sure all the sealing surfaces are flat and true (file or sanding block helps), hardware is all clean and runs smooth, gaskets are good quality. I like to use a wipe of sealant on everybody. install everything finger tight loosey-goosey and get it all adjusted and then tighten equally so that nothing is bound up or stressed.

locktite at your discretion.

Don't forget the split washers for every nut/bolt!

^^^^ This! You should expect that every flange surface of each exhaust component is out of flatness, especially aftermarket.

Great -- thanks all for the good advice.

I noticed that on the head and intake pipe, there is a flat and split washer for each nut, but it seems like on the exhaust elbow there is just split washer. I think that's right from looking at the space cast in the elbow for the washer. A flat washer won't sit in there but a split will.

That said, when I get this all buttoned up and back in the scoot, I will have a Pollini exhaust and no elbow. Should I add flat washers? Seems like the edge of the split washers can get hung up in the bolt hole on the flange. Perhaps as they say, this is mox nix.

If you have enough thread, add a flat washer. Anything to help with the vibration and expansion/contraction!