Steve, if you haven't already done this, you should try this first. The 4 philips head screws that hold the top covers over the diaphragms need taken out. remove the diaphragm & slide, clean the metering needle and the jet it rides in. Steel wool the needle & a pipe cleaner with carb cleaner in the jet. If a V12 sets longer than a month, the gas builds up on the metering needle & jet sides, reducing the fuel flow. There is an index tab on the rubber diaphragm to align when installing. Top up the oil in the plunger chamber.
Cheers Tom
