If it uses carpurator then ask the work shop to clean the carpurator. This piece of equipment is very sensitive, while it looks like < 15 parts inside.
If it is fuel injection, then I don't know. Fuel pump (cheap), or water pump (expansive).
Charge the battery to full charge is a cheap way ($10) so isolate problem due to your weak battery (if you suspect weak battery). I believe fast charge takes 2 hr, slow charge takes 4 hr