ARE YOU BACKFIRING AND IT STARTS OR NO START? As Martin and Joker are advising, backfire is usually timing. Could be 180 deg out of phase. The ball will come to window at two Top Dead Centers. One compression, one Exhaust. You want the compression TDC to then wire plugs. Find it many ways, look at valves, thumb on hole or putting Kleenex in hole just snug. It will shoot out hard at compression stroke. NOT down in hole, just blocking hole. It's better to do this finding compression TDC with all plugs out and center dizzy wire off.
You can also just move plug wires 180 deg on dizzy clockwise (CW). Don't move dizzy, just the wires. Move no. 1 wire on dizzy cap three holes CW, then wire the rest to 1 5 3 6 2 4 CW. And see if it starts. You will, of course, have to use whatever wires reach the plugs with the new orientation.
