the Gen II "doo" lever is stronger but the spring is too long & gets loose. if the bike has more than a few thousand miles on it the spring will have no tension. many are so loose they literally fall off. they have been known to go through the timing chain and make timing jump. (BTW, the lever is a poor fit to the shaft which lets the whole works stay in motion while the bike runs). actually the whole design is piss poor & then built with crappy parts.
anyway, what I was getting at is that if you have spark & shoot some fuel into the carb & it runs, then the fuel system is at fault.
if you have a spark & shoot fuel in and it still doesn't run.... either:
(1) there isn't enough compression due to tight valves, jumped valve timing (with possibly bent valves), broken rings, blown head gasket or most likely a broken compression release. (a head gasket that bad prolly leaks coolant too)
(2) the spark is not at the right time. this sometimes happens when replacing the doo. in the process the rotor has to come off... when it goes back on it has to engage a woodruff key on the crank, if that gets knocked out during assembly the rotor will eventually slip on the shaft. it might still spark, but the timing is way off