1978 Mercury 700 runs and then stalls

[SPLMAXSAM]

I have an interesting problem. I have a 1979 Mercury 700 outboard. The problem is that outboard will run for a short period (several minutes) of time and stall. I think the outboard has lost its prime and stalls.

I have tested with 3 different tanks / fuel cells, 2 different hoses and 3 different primer bulbs. The outboard will run for a short period of time and stalls. I can reprime the ball and get it to start but it will soon to stall.

I have bypassed the interior fuel filter and have added an aftermarket fuel filter

I am suspecting a fuel pump. Any suggestions what I should do or try?

BOAT - 1984 MirrorCraft King Fisher

Outboard - 1979 Mercury 700

Fuel - tank and cell

(fuel cell before VENT and fuel gauge sender and grounding)

 

[ajgraz]

Re: 1978 Mercury 700 runs and then stalls

Does sound like a fuel pump diaprahgm, pump check valves, or possibly a carb clean/rebuild. Look for posts by me, RaScLeS and PHE for commisseration with that motor.

Beauty boat, BTW. My next rig might be very much like that for bay and kelp use here in San Diego.