Scooterotica

I was reading the Vespa big box exhaust review in Scootering and it seemed they had to down jet these I'm most cases.

I thought it was usual to have to up jet a bit when fitting a 'performance' exhaust?

Andy seems to have started with a slightly over jetted P2 motor with a SIP 2 road on and to have had to down jet for most of the other pipes on test. Is this simply that it was put on the dyno and it could be dialled in properly?

Fairly sure that was spoken of in here somewhere recently but I'm buggered if I can remember in which section or thread.

Also mentioned going up on the pilot jet too?

any chance you could post the article?