The other night on the late '84 Sportster with Keihin carb cleaned the jets and the bowl, accelerator pump, and accelerator pump spray nozzle. Diaphragm looked bad, cracked and see through but it was late and it went back in and I put it together to ride. I didn't notice until later when I was putting it away that the rod that pushes the diapragm wasn't in the hole, it was just dangling not being used; probably lucky it didn't fall off during ride.
But it started easier than ever and rode better too.
Today it got a new diaphragm and spring, and the pump rod put back in use. Starting was difficult, acceleration crappy in fact couldn't roll on it, and it coughed and backfired and wanted to die. And it didn't want to rev up. Was able to get good idle after warm up. Might have put a hi-flow Andrews accelerator pump on it a few years ago but not sure of that though since the bottom of the bowl doesn't have the factory hole welded up or the hole drilled as in the Tech Tips and Tricks Vol 2.
so how about riding without accelerator pump? the other night while riding without it, it ran fine but never did have to hit it hard. or am I missing something else. not sure what jet sizes I'm running.

 

accellerater pump has nothing to do , after you roll the throttle..
so it is not your problem .
find a friend that understands the carb , and will help you .
the internet aint gonna do it from your description.

 

I'm not familiar with this particular carburetor, but I've seen many. It is possible, depending on design, that a cracked diaphragm can cause additional fuel provided to the mixture enriching it. After you replaced it your engine started running lean. Backfire is typical for lean mixture, in particular if acceleration pump is not working and you open the throttle.

 

So I bought my softail chopper with a std panhead motor 6 gear trans. Ran good for a while other then it pukin oil out my crank case breather after ever ride. I was riding home and it sounded a little funny when I started it like it wasnt running on all cylinders. When you rev it up it kinda sputterds. I changed all 4 plugs they were super black I started it sounded perfect reved perfect. I go to ride it and it sputters again and acts like my gass is off. I got to down **** to keep up speed and if I give it full throttle it falls on its face and jerks back and forth like its outta gas. And it doesnt back crackle like normal. Anyone have any idea what it could be. I hope my description is helpful. I have an s&s super e carb. I don't know if its valves or accelerator pump maybe carb tuning ignition or what I'm cluess

 

1974 ironhead 1000 new performance moded HD cv 40 2 into 1 pipe with muffler mac pipe. Runs strong across power band. Off idle spit then goes well. Runs 45 slo jet 180 main dyna ele ign. Free flow air cleaner. Can acclerator pump be adjusted to counter off idle spit?

 

I don't know the exact details but I was talking to a guy at a custom show who told be that there is an alternative nozzle that delivers a mist of fuel rather than a squirt . Apparently this makes a big difference to performance .