SpudFiles

first find a pill tube and a pen tube click to see and drill a hole the size of the pen tube. glue it in.
buy a long nose lighter click here to see and split it in half. (click here) take out the piezo (sparker) and it should look like this. find 2 strong wires that it is hard to bend and cut one about 3'' and the other 2''. conect the longer one to the back of the piezo and the other to the wire. take your combustion chamber and put 2 small holes the size of the wires you conected to the piezo. they should be about 4-6 milimeters apart. insert the wires in the holes so the wires are about 3-5 milimeters apart. glue the piezo the the chamber as shown here
now you dont have to do this but if you want a butane injector then put the lighter back togather like this. that way you just stick it down the barrel and give it a squirt.
that should help but experiment before you do any thing so you know how to do it not just can do it. learn how it works and stuff.
any questions just ask

here is a video of it sparking

and here is one of it shooting