[L Prete]

here's what I know.
both sets of points are sparking.
engine runs primarily on left cylinder except at higher RPM, then it seems that the right side is firing (I assume because the right exhaust heats up)
with the engine running and the right plug out the, the right plug sparks consistently.
getting gas to the right carb.
most of the time the right plug is wet (and black) when inspected.
any suggestions?

 

[HerrDeacon]

Could be low compression on the right side (or even both). Have you checked it? Also, check the valve clearances, they could be tight causing some compression loss.

 

[lugnut]

See if your right carb's float is taking on gas (sinking.)

 

[66Sprint]

Carb flooding on R/H side.... cylinder runs when fuel need of that cylinder exceeds the flood rate...(enough air gets in to create a burnable mixture). Check float level, idle jetting, and shut-off needle and seat.....