Piaggio Zip 50 4T Year of construction 2006/ Lief, went out and since then no longer starts!!

Hello dear forum, I have a scooter as stated in the title. Did run it this morning after 2 weeks still, for half a minute he ran well and suddenly went out, found that he no longer has a spark. I then turned off the spark plug plug and held the finger on the cable when starting (by e-starter) and felt a small amount of power when starting, but where more power should be. alternator works. However, the CDI brings to we nig electricity, but it brings electricity, i.e. that it works. What is the reason that it provides me with too little power for a spark? When it ran half a minute before it is out, it ran without any objection. Have there a few weeks ago new parts like: – voltage regulator – spark plug – new air filter mat and new brines (completely) installed. After that he ran great, then confessed and now that. Can one help me ? Thanks in advance Dennis !