look down the throat of the carb and see if when you open the throttle lever there is a stream of gas shooting out. if not that could be your problem, the excellerator pump isnt workin thus not giving you an initial squirt of fuel to start it with. probably not your problem since youve already tryed starting fluid but alot of possibilities exist. you might also check fire for strength and see if it will jump a gap of about an 1/8" at the plug end while cranking it over. if not it could be from low battery voltage ( discharged or bad battery) weak coil, not enough voltage at coil while cranking, short in dist ( not too likely), cap or rotor or wire problem. check fire on more than one wire. look for carbon tracking lines inside cap and burnt spots too. Good luck and hope you get er fixed.
67 M725, 67 M715, 68 M715