Fuel Pump
peterg,
When you had the pump apart did you remove the top casting to expose the diaphragm ??
When re assembling it is important to hold the priming lever in a position to pull the diaphragm down from its central/natural position , otherwise the tension on the diaphragm will be too great to allow it to work correctly at higher revs.
I bought a simple pressure gauge and adapted it to a spare banjo bolt to check the running pressure of the AC pumps when using Solex carbs. From memory pressure should be about 2.5 - 3.0 psi . I once had a problem with a engine lacking fuel under load , at idle and cruising it pumped about 2.5 psi but once under load going up a steep long hill the pressure dropped away to about 1 psi.
Having to prime the carbs after a few days of not running is common,
it is often caused by the emulsion tube holders being loose in the carby body (originally a press fit , but I carefully remove them and Loctite them in , to seal them) , where they enter the body is below the fuel level so over time the fuel in the bowl leaks out through the carby throat into the engine .
Over a longer time fuel evapouration occurs to what fuel is left.
Geoff
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