Fuel leak - help !

[steve.thomas]

Hi All,
Fiddling around after a short run I noticed some fuel collected in the engine bay just below the carbs (Dellortos) on my Plus 2/S130. Couldn't see any obvious sign of a leak so I removed the outer air box and found fuel collected along the inside edge of the part still connected to the carbs. Again, couldn't see any sign of a leak, but the large nuts where the fuel pipe joins the carbs where not very tight - tightened them slightly. By now most of the fuel had evapourated so it's only leaking while the engine is running. Having the airbox off I decided to check the carb synchronization using a balancing tool. The engine starts and runs fine, but within a few minutes there was fuel again collecting along the inside edge of the airbox - it seems to be running out from the air trumpets. Clearly this can't be normal - any ideas on the cause greatly appreciated?
Thanks
Steve

[billwill]

Is the float valve dirty/worn & failing to close off the fuel when the proper level is reached?


Excess fuel pressure due to fitting an electric pump without also a fuel pressure regulator?

[steve.thomas]

I don't have an electric fuel pump, but I haven't checked the float level yet - job for tomorrow it seems.
Thanks for the suggestion.

[steve.thomas]

I decided to remove the carbs and strip them down for inspection. What I found was that the venturi in one barrel was loose - it's held in place by a grub screw and locking nut. Elsewhere on this forum confirmed this as a potential cause of fuel leakage. I also found that one carb had pump jets forward facing size 33, and the other with vertical holes size 45. Eurocarb in Reading were able to supply me with 4 size 35's as per the manual. After some balancing and mixture adjustment the car is running much better and no fuel leak - yippeee !!