Briggs Boggs

This is an 18hp L head Briggs. It ran ok but not quiet smooth even after replacing point/condenser and plugs so next I went for the carb. I soaked it overnight, washed it thoroughly, sprayed carb cleaner in the passages, ran a FINE wire through the passages then blew it all with air. Put a kit in it, reinstalled it, but now there's a new problem I can't figure out. When I throttle it up fast from idle it'll die UNLESS I pull the choke on. If I slowly increase the rpm's it's ok. I also set the float level so it's good. What's causing this? Fuel starvation maybe? How? Has a new fuel filter, the flow is good, and I also replaced the pump diaphragm and springs. I'm stumped!

If the choke overcomes the problem then it is a starvation or air leak problem.

Last one first.
Get a trigger spray and saturate all around the carb & the manifold with the liquid of your choice.
I use WD 40 cause it creates a lot of white smoke when sucked into the engine & burned. Just don't use any fuel of any type in case you end up with toasted eyebrows.

If that tests out good then back out the idle jet a little.

The description 18 Hp Briggs is about as usefull as double sided toilet paper.
If you want better information, we need better information like the full engine numbers.
Your engine could have any one of 6 different carbs, each with their own pet problems but we have no idea apart from it is an old engine because it has points.