replace the batteries for $50 or get a new electric scooter or bike,maybe one with more power.
if you have lights on the bike or scooter they should be powered by a separate battery so it doesnt take away from the power.
2-stroke in frame engines can be a lot of work to put on and mantain.
get a new scooter or batteries then when youre 16 or so get a engine kit so it will be legal,no one wants there hard earned bike taken away.
plus you can upgrade your electric one with more powerful motor and batteries.