Re: Is that a popping I hear?
if it's a steady, rythmic popping, it could be a stiff link in the chain. if you spin the back wheel very slowly, watch as the chain rolls off the rear sprocket. you'll see the chain bend unnaturally, like one link won't straighten out right away. it usually happens where you re-joined the chain after removing links.
if that's what it is, to fix it, spin the wheel till the link is in the middle between both sprockets, then grab the chain with both hands on either side of it and bend it back and forth, the way the chain's not intended to bend. that will work the stiff link back into shape.
could also be normal. these bike's make all kinds of weird, imposing sounds.
as far as removing your pedal chain, then you'll have to scooter your bike around to start it.