1st option: Gianelli Sachs pipe. Will need to make a bracket for the left side. (Hard to Get) Works great with stock cylinder
2nd option: 2pc Biturbo for Tomos. Just the Expansion chamber half is needed. Must weld or clamp to your header. Sometimes this requires you to cut the header from your stock pipe. Will still need to modify or make a bracket for it though it will exit like stock. (questionable gains)
3rd option: Simonini or similar pipe for Peugeot. Must make spacer from old exhaust to fit inside Simonini header. Must make bracket to fit. Exhaust will exit on the left side but is shorter than stock. (this pipe maybe a bit much on a stock cylinder, its huge)
Carb Options: These motors love a new bigger carb. Big gains
1st option: 13.5mm Mikuni or similar style Mikuni (I bought mine from Smitty but he no longer sells moped parts) Sits at an angle but fits fine. Can use Puch Bing Hi-Flow filter. Your choke cable can be made to work with this carb. I believe I just took the choke elbow off the carb to make it work. Need to rejet carb. Mine needed smaller jets.
2nd option: 15mm Amal. Modify the intake spacer by grinding out material till it will fit over manifold. Get a filter that fits dellorto PHBG. May need to upjet the main jet. Stock is #45. ( problem I need to find a different needle to use with this carb. Mid throttle settings are way to rich with no adjustment left) Worth 2mph at WOT over Mikuni on my bike. Which is something because the mikuni was worth about 4mph over the stock bing.
3rd option: usually with Sachs C or D motors there is the option of making a spacer for the intake or turning the intake around so it faces forward and using a Puch Bing. But with an A motor you don't have this option because of the angled cylinder and intake.
13.5mm Mikuni, Hi flow filter, Gianelli Exhaust, 11x40 gearing 38mph on a flat road.
15mm Amal, K&N Filter, Gianelli Exhaust, 11x40 gearing 40mph on a flat road.