This has been a popular subject for remedies and bandaids to nullify the vapor lock issue. One poster on the FBBO forum found that the current ethanol added fuels, especially here in Cali with more added chemicals, start boiling at around 150*. Think about that. Your engine is running anywhere from 170* to 220*+ just in the coolant. Add in the extra heat from what the exhaust, external surface area of the engine, accessories etc generate to add on top of what your gauge shows. Since the boiling point of the fuel is way lower it seems the venting systems that used to work now cannot keep up with the extra vapor pressure being generated. If you are able to get unadulterated gas, that would be your best bet otherwise you'll need to see what others have done to get around the situation. Like adding EFI to your ride.