VAPOUR LOCK PUMP BUBBLE

[plasticpig72]

when my 3000S is hot and i stop there is a bubble in the glass dome of the mechanical fuel pump.
After when it has cooled down the bubble disappears so this must be vapour lock. On the dgas i still have an automatic choke which will also transfer heat to carb and fuel inside it. Could this cause vapour lock in carb also. Perhaps a manuel choke is better to keep the carb cooler + electric pump away from engine heat.
Alan

[GAjon]

Check the run of the fuel pipe along the chassis rails, they sometimes run very close to the exhaust manifold and can cause vapour locking.

[plasticpig72]

that's a good point i didn't think of the supply from the tank running along chassis rails close to the exhaust. I'll have a look to see if it needs insulating from exhaust pipe heat
Alan

[plasticpig72]

I have solved the vapour lock by fitting a Huco electric low pressure pump(for webers) in the boot. I can switch it on when the weather is very hot or in traffic jams. This means there is a constant flow to and from the carb in the return line to tank. There is a restrictor in the return line so the carb will be feed first. For info the Huco pump is very quite not like others
Alan