You are drawing air, my friend.
You may think of using a pressurised system.
Any of these pumps
will do it....
Electric Fuel Pumps
- Stewart Warner
They are not expensive, at about $80 or so.
Using a pressurised system will add to the fire risk, but the starting reliability of the motor is transformed. You can put the fuel pump
on an on/off switch. Once fitted, you simply cannot get an air leak downstream of the pump
. You can get the occasional fuel
leak, but you see where it is leaking out and you can fix it.
Crucially, the motor won't stop in the meantime.
Without the electric pump, I had the motor stop more often that I could tolerate.