CVP Carb kit installed and having adjustment problems

Hello all,

I have a 1997 Sportster 883 hugger that would cough and backfire upon quick acceleration. I thought it was typical sportster cough or a dirty carb, so I ordered the CVP carb kit, pulled the carb, did a nice deep clean (it was dirty) and performed the carb kit install.

To start, the carb must have been played with before because it had two shims on the needle, a 180 main jet and a 45 pilot jet installed already. The carb cover had also been lightly siliconed down tot he top of the carb.

So, I changed the jets to the 44/175 as noted in the install instructions, installed the new spring, needle (with no shims) and emulsion tube, drilled the slide and installed the easy adjust mixture screw. I also cleaned any sealant off the top of the cover and the diaphram.

Now, when I start the bike, it will idle ok, but I blip the throttle and you can see a decent fuel spray coming out the carb and it backfires a flame out. Idle mixture was started at 1-3/4 turns out and brought out to 3 turns with not much change. The backfire seem to get "better", but when I rev up the engine, it hesitates for sure and takes a bit to get up to RPM.

What is the next step? I seems I took jetting out of the carb when I put this kit in so I wouldnt think it is getting too much fuel, but I could be wrong. I also have to keep putting the carb back on the intake because the previous owner had a crappy aftermarket filter assembly on it and it doesnt hold the carb on. I have a new one coming.

Also, I did note that there is a slight burn mark on the slide plastic, but not very much. the diaphram seems to be ok.

Thanks for the help! Bike only has 2500 miles on it original so I know its not real molested.

I also installed new plugs as well...