1998 Sportster 1800 - funny business around 3000rpm

[lauramsportster1800]

My port side 717 has been giving me problems. Had a quote last year to rebuild the engine, carbs and pump. Couldnt' do all three so i did the engine. She starts up perfectly fine, but for the past couple months it is really finnicky (sputtering, dying) up until i open past 3000 rpm then its perfectly fine, super powerful. So i pretty much have to turn it on and immediately rev to half throttle.
The past few weeks however it seems to be the opposite. Still starts up on a dime, but now it idles perfectly stable at about 1.5 goes smooth up to 3, but as soon as i try to take it past 3 it completely loses its steam and goes back down to idle.

I know the answer is probably rebuild the carb and get a new pump like i was quoted... but would anyone be able to more specifically give insight to what aspect is causing the issue? Im in southern ontario and completely out of luck in terms of any shops that will work on it.
Thanks!

 

[lauramsportster1800]

Few things I just thought of that may add context….
1) Batteries die slowly, I realize this is probably my resister that needs to be replaced
2) as I said new engine last year. This happened beforehand too so I don’t think it’s the rotary valve or anything engine related
3) there is some funny business at times with the throttle. At random points when I’m in neutral it will throw itself into forward. Also reverse… doesn’t really work
4) the starboard side has never had a single issue. Always turns on right away. Accelerates, decelerates perfectly.