1989 Mercury 25hp won't stay running

I've had a 89 Mercury 25hp long shaft since spring and haven't been able to get the thing to run right. I haven't put a ton of time in it recently as I have been busy with other projects. I have replaced all seals in the carb, as well as installed a new fuel tank and line. It fires on one to two pulls and runs for a minute or two after that. I have tweaked the adjustment screw on the carb, with little to no improvement. It runs, but dies after a minute or two. Takes even less to die from anything above an idle. It appears to be flat out running out of gas. Like it starves itself out. I can hear when it is about to happen, and to keep it running, I can squeeze the ball and get it to go for another minute or two. At this point I'm just hoping there is a simple fix because it seems like I'm so close to having it work. Any thoughts??

Re: 1989 Mercury 25hp won't stay running

Rebuild your fuel pump.

Re: 1989 Mercury 25hp won't stay running

+1 on rebuild fuel pump .... here is another odd ball thing that can cause it. When you put the gasket on that goes between the carb and the block, make sure the gasket has a small hole in it and you put the gasket on correctly to line up the hole in the gasket with the hole in the block. That is an impulse line and your fuel pump will not pump if that hole is blocked. I had a bad gasket and I made one until I could buy one, I forgot to punch that hole and the fuel pump would not pump. It would run as you described, just a bit and run out of fuel.