1st of all Im definitely not a moped expert so excuse my knowledge of my parts but, I purchased a 1977 Vespa Ciao Piaggio. Dude had it bored out ( I have original parts ) I’ve had it for a month. It would start right up and do 45 easy then one day I felt like it may have been acting up but maybe not. On my way to work It popped and It lost all power all at once almost so bad that I lost balance, then it slowly sputtered to a stop. I was able to start it after but only enough to get myself somewhere. Then after that I let it set while I went to work and after I went and got it and drove it home it died. The dude originally had welded the pipe right above the exhaust outlet where you mount it on the back frame. And it had came loose. I purchased a new exhaust. Now It sounds like it wants to but won’t and dies, pulling throttle doesn’t help. It has ran on the new exhaust, I also don’t have rear brakes I did but they quit, it’s not the brake cable tho. Oh and the manual petcock was leaking but I ordered a new one. Please help. Sorry if this is a little hard to understand.