2002 mercury 300x promax fuel delivery

[robalo24]

Both engines were running well from the ramp...few days later before airshow...both were warming up...starboard stalled...no big deal...wouldn't start back up...still went to airshow on one..lol....got back and got it running on a spray can......Popped line off outlet on manual fuel pump..and cranked it..no fuel comes out...cut and dry I have rebuilt several diaphragms on my v6 old carbies ...should I presume that the secondary electric pump is ok?..or does that secondary pump assist the manual in fuel delivery....thanks in advance alien cowl masters..

[vnemous]

the manual pump feeds the vst which supplies the high pressure pump. The high pressure pump does not assist the manual pump. There is a chamber in the vst with a float that maintains fuel source from manual pump for high pressure pump.

[robalo24]

Thanks vnemous...I will do the diaphragm n see what happens

[robalo24]

Rebuilt manual fuel pump with oem diaphram kit...now she is running mint