I would turn the carb around so the fuel bowl is forward facing. Modifying linkage isnt too bad. Ive had that problem years ago with other carbs due to gas splashing into carb. If you take off the filter and look down into the carb you may see where there are two little vent holes going directly into fuel bowl where fuel can also come though if you stop hard enough, regardless of float level settings (if i remember correctly). at least on the 38/38 weber. Personally, i would lower pressure to around 3psi also.