Mikuni Carburetor Jig

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One of the biggest challenges when removing idle mix screws from Mikuni BS carbs is getting a secure grip on the screw while holding the screwdriver straight, applying enough force to keep it engaged and turning it with sufficient torque. Knowing this in advance, I decided not to be bothered spending an evening designing and building a jig using SolidWorks, calipers and a carb body, which would hold the carb relatively securely, allowing me to work on the screws more easily. The design turned out pretty well and worked perfectly for removing the screws from the first two carbs by leaning on the end of the screwdriver with my chin and working it back and forth until it came loose. After completing two carbs, however, my chin was sore. A couple of days later, I developed a sunburn-like peeling sensation. A week went by before I had an idea to chuck a screwdriver bit into the drill press, giving me mechanical advantage through the quill feed, which would automatically keep the bit straight and let me apply plenty of torque. Using this method, I was able to remove the third carb's screw, even though it had already been rounded out in its slot. You can see how much torque I applied using the drill press. The jig says BS32SS on its side but a BS34SS fits into it just fine, and something similar could probably be tried with blocks of wood before cutting a hole through the tower and screw. A better quality bit than the one from ACE hardware would likely withstand more torque.