Is it possible? compression on all 3 is even, I've tried various jetting setups, changed plugs and trimmed the plug wires back, but the mag side plug is still covered in oil when I pull it, and the sled sounds like it's stuttering a bit in the midrange if I punch it, but if I hold the throttle a little bit open for a few seconds it doesn't stutter at all, I'm thinking that it's dumping too much oil in at low rpms and when I run it at slightly higher rpms before punching it it's clearing the motor of excess oil.
Oil is injected at the fuel pump, All carbs get the same ratio.. Sounds like you have a dirty carb or its not tuned/jetted properly. Check and clean the jets and set air/fuel screws. check compression and reeds also. How many miles on sled?