Gilera runner 125 - had the bike for 4 years it has always run smoothly. I woke up the other morning to go to work and my bike would only go 45mph when I did 70mph please help me!! I don’t know anything about bikes either so a basic explanation will do :)

SOURCE: gilera runner ignition

When you encounter this type of problem the best thing to do is find a fab shop that can reproduce the tube that was ripped away. I frequently did these types repairs when I was running my shop. It's not really that hard to do, you just need a lathe and some shop tools and a tig welder to fix it. If you have to pay to have it done it might cost about $100.00 plus you will need to replace the ignition that was destroyed.
I feel for you, most likely did not catch the thief either. If I still had my shop I'd fix it for free for you.
Good luck finding the fab shop you need.

SOURCE: my gilera runner 125 vx

put choke and start the bike in the morning

SOURCE: gilera runner vx 125 oil change?

Its the really big bolt on the right hand side

SOURCE: my gilera runner vx 125 wont start

i had the same problem if i remember correct it was a T shaped connecter for 3 tubes that had snapped cost about 50p

SOURCE: gilera runner vx 125cc wont start

check for a loose wire on the relay or battery, or selionid