From my thread search this seem a not uncommon problem. Down here in the Dung country's lanes I frequently have to brake hard and dive close into the hedge to avoid large 4x4s who seem unable to get anywhere near the hedge on their side. The engine usually dies on anything more than gentle braking. My carb is a BG 650 double pumper speed demon and I am led to believe that a surge goes up the vent pipes on either/both the primaries and secondaries and temporarily drowns the engine. Is this correct? Would adjusting the float levels change this? I saw a post which said that connecting the primary and secondary vents with a small pipe pipe vented at the top of its arc would help. Its getting so that I can't rock up to any junction enthusiastically without an embarrassing stalling moment. Any advice would be gratefully received.