To me, the rectifer isn't used to create a spark (re: spark plug).
A rectifier converts AC (produced within the stator assembly) to DC and its built in Regulator allows your battery to charge - but not over charge. For more details, surf:
http://www.rickystator.com/pages/Single ... lator.html
If you've replaced the Stator assembly, external coil, it might be the CDI. It could also be a bad connection within the electrical system or an improperly set safety switch - like its tether cord NOT plugged in properly. Could be crud in the key switch and even crud within its red kill switch. When the complete wiring / switches have been double tested, then focus on a possible bad CDI.
Note: If you need to purchase a new CDI, you might want to install a 3rd party non-rev restricted CDI. A few more dollars then stock but if you need the extra engine RPMs, you'll have them.
Hope this helps....