working with an 03 p650 front plug keeps fouling

 

Sounds like the front carb is running rich. Try adjusting the air/fuel screw on the front carb. The stock setting is 2 1/4 turns out (counterclockwise). Close it up (turn clockwise) to make it leaner. Another cause may be that your front carb choke may be stuck open due to a weak choke spring. Replacement spring part # is 92081-1720. After tweeking the carbs, resync the carbs with a mercury carb tuner guage. I have a Carbtune model. Motion Pro also makes a good one. Anyway, start with adjusting the air/fuel screw.