(quoted from post at 17:02:39 09/30/13) If eng has point/mag or solid state ign,wire to eng ign on wrong terminal of ign sw & is being grounded in run position rather than the off/stop position killing eng ign.Disconnect wires on ign sw,with sw in OFF/STOP position with an ohmmeter check between sw shell/battery neg(-)and all terminals on sw,if you get a reading one one terminal,leave meter connected to same & turn sw to ON/RUN position,if meter reading disappears connect lead to eng ign to that terminal,If sw has a G terminal on it you might have to connect a jumper wire from G terminal to chassis/battery neg(-) to get a reading.Reconnect wires to battery /s/g or sol for same.
If eng has points/12v ign coil you probably have ign lead connected to wrong terminal & not provideing +12v to coil in ON/RUN position,with sw in ON/RUN position(leave battery/wire to s/g or sol for same connected to sw)with a voltmeter/12v test light check each sw terminal till you get a meter reading/light,turn sw to OFF/STOP position,if meter reading disappears/light goes out,then connect ign lead to that terminal.
For s/g wiring goto link below & wire according to what best matches/suites your needs,move mouse pointer over pic & click left mouse button to enlarge drawing.
wiring