Px 200 with exhaust malossi

Hello

i am quite new in the vespa community and i am recently owner of a vespa px 200. Now i purchased a malossi exhaust and i was wondering which mainjet i would need for the right setting of the engine to work properly.

the engine is an original with serperate two stroke oil

thanks already for your comments!

i was running a 125 main jet on my px200 engine with a malossi exhaust.