yamaha 25-3 cyl issues

[redfish150]

i have a yamaha 25hp - 3 cylinder, bottom cylinder not firing.
Pulled each plug to determine that bottom cylinder not firing.
Swapped the 3 coils around moving the top and middle to bottom and still no fire.
Changed the CDI (power pack) and still no fire at bottom cyl.
Good compression - 120 all 3 cyl
getting fuel at all carbs

Any suggestions?
Rectifier? should i change it? could that be it?
Thanks