Motorcycle Repair: carbueration, air fuel mixture, air fuel mixture screw

Question
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Followup To
Question -
I just finished a total rebuild on a 1980 shovel. The only engine mods are a "J" grind cam from Andrews and a contact ignition from Accel. I am trying to use the stock Keihin carb with a Youst power tube. The bike started easily but would run very rich off of idle. I readjusted the float setting and readjusted the idle mixture screw to 3/4  turn off seat. Now I cannot get the bike to start. Do you have any suggestions?
Answer -
Did you have the bike running before the rebuild with the same carb? Also, pull the plugs and let me know what color they are and if they are wet.
Mike

Follow Up
The bike was running with a different Keihin carb. The spark plugs are wet, black. I tried tuning down the idle mixture jet but would not get any fuel.

Answer
Your plugs are oil fouled. You will need to change them to ge them to work. Turn the idle mixture screw up so you can get he bike running. When you get it running and let it warm up, slowly turn the air/fuel mixture screw inward until the bike starts to stumble and then turn it out around 1/4 of a turn. Take the bike for a ride and see how it runs. You might have to rejet the carb.
Good luck and happy riding
Mike