I have an internally standard 49 Briggs V-Twin with a billet flywheel, I have fitted the billet aluminium adapter to the Nikki carb with an after market air cleaner (as from EC Carbs). Wondering if someone could give me some idea of what size the main jets might need to be drilled to. Standard they seem to be 1.3mm. I have tried 1.8mm and 2mm but off the line (standing start) the engine bogs and won't pull hard. Any helpful info will be appreciated.