i know a similar post was asked about this issue back in 2006 and ive checked out all links and advice but still drew a blank and i would be much happier with piece of mind knowing i can kill the quads engine -50cc as sometimes my child gest too excited & panics abit and forgets to let go of throttle and twice ended in a river and once in the middle of a very prickly gourse bush lol ( in not intrested in coments regarding my child being not ready for the quad as we have to learn sometime cheers )

 

What brand of bike is it?

 

Search Ebay for "remote kill switch" They run between $50 - $70 and have a range of 250 feet.

I added one to my son's LT80 and it works great. They have different kits for electric start and pull start models.

 

here's the link remote
look under sla109 parts, price is $27.36 for the complete remote control unit

 

it is a rebo pocket quad 50cc with pull start i only chose this quad because she trashed the last two lol