sorry guys I lost this post. The shoelace thing is a lanyard in the left rear wheel section under the fender it is a safety plug if you fall off or your youngster starts to get away from ya ya pull it and it pops out and kills the unit. There is also the electric lock out set with the car fob that does this as well.
it looks something like this
Tether Cord: Camping & Hiking | eBay

 

 

Could be wrong, but "extra" wires usually have either a connector on them, or are just cut off. That seems to have a special shaped end, which is often used on areal wires. If the machine has a remote kill box, that will be the areal for it.