Running poor in mid range

[JohnDeereJack]

Hey guys my name is Jack and I'm new to motorcycles, I just picked up a bike for a project and its a 1982 GS 450l, the bike only has 2900 miles on it and besides being dirty its in really nice shape, the problem im having though is it struggles to get out of the low range rpm, it will idle fine, but then struggle and sometimes die when I try to rev it up, but if it successfully makes it past about 3k rpms it runs like a dream, getting it past the low rpms is the problem. I thought this could be plugged pilot jets so I took the carbs fully apart, cleaned and replaced gaskets, inspected all lines and boots for air leaks, cleaned the air box and put it back together, It runs a little better but still has the same problem. I did a compression test today and its reading 125 in both cylinders which I thought that seems a little low being that the bike has so little miles but im not sure, any help is greatly appreciated!!

[LAB3]

You hadn't mentioned the petcock, make sure the pickup screen is good and clean. When you cleaned the carbs did you dip the bodies in a solvent like Berrymans or Gunk?

[Gorminrider]

^^That,above, and : when you get an old bike that isn't running right you have to do things...
obviously a "going over" and "troubleshooting" extends to spark plugs,coils and more but given your particular complaint per "improvement" and "compression" I'd start with these:

engine= check/adjust valves THEN check compression (throttle must be wide open for compression check)

fuel= carburetors cleaned including main and idle jets REMOVED and cleaned (tiny holes in jets avoid making them bigger) float levels and checked for float needles able to seal (float level is useless if they can't actually STOP fuel flow when bowls full) ... correct operation of "choke"

electrics,ignition= all bullet connectors tight,clean-look especially for "mods" and aftermarket connectors... and good "grounds"-especially the black/white stripe wires from the ignitor box. Also check the "sensor" that will determine spark advance...

one of these may "fix it" but don't stop there. They all have to be done anyways plus brakes checked etc etc. AND a shop manual: here
GS450 Official Service Manual PDF