I have a 97 Honda BF50a carbed.
I had a fuel problem. New Line bulb and filter, Also cleaned the carbs. (re-used the iffy manifold gasket) I have good pressure from bulb to filter, but I can only keep it running if I have it 1/2 choked. Fuel Pump?
Only keep it running on the idle, or keep it running at a higher speed? Dicey gaskets can cause a vacuum leak. A big enough leak is going to have you pulling your hair out at lower rpm. Easy to check for sure though. With the engine running in a well ventilated area, squirt ether around where the gaskets go. Doesn't need to be anything precision. You'll hear the engine change sound/speed if sprayed near a leak.
If that doesn't help, go back into the carb and have a better look at the low speed jet in the bottom of the tube in the middle of the carb, that runs from top to bottom. Those are about the size of a human whisker and MUST be clear to get the engine running right. Also, the tiny o-ring that reside on the top of that tube need to fit snug, or the vacuum is not going to be able to pull fuel from the float bowl correctly.
When I first started doing these carbs, there were a couple of sets I had to go back into several times to get them right! Many pros won't mess with cleaning them, they automatically replace them on any carb clean they do. Myself, I'm not in that big a hurry for what they cost.... -Al