Honda CB125T Extreamly high idle

I have had problems with the bike for some time. At high rpm bike started stuttering and losing power and the problem got worse the hotter the bike got. Cold starting has also been really difficult but when warm, it starts on the first kick. I tried all the basic stuff and changed the whole ignition (points, condensators etc.).

After winter I did some basic maintenance: Cleaned the tank, new fuel lines, cleaned the carbs and switched the main jets from 88 to 90 to see if made difference at the high rpms. When the bike was running right before i tried 90s because they were suggested for more torque, but I noticed no difference so I switched back to 88 then.

Bike was really hard to start (50 kicks) and when it started the bike immediately overrevving. I though a slide was stuck or something and I tried a lot of other stuff. At first idle is around 5k and when the bike warms it gets closer to 8k.

I put new o-rings on the intake manifolds and tired to seal them with better clamps and duct tape with no effect. Also tried spraying intake manifolds with starting fluid, which had no noticable effect. I also tried sealing the slide caps better.

I tried to feel the carburetor slides through the air filter and played with throttle and both slides seem to go all the way down. Slides are adjusted to go as down as they can.

When the bike was warm, I tried to start the bike with right spark plug wire disconnected and it had no life. When I did the same, but removed the left wire, bike started immediately and was idling 5k on only the right cylinder.

When I ajust the left carb or block the left air filter intake, it has no effect. When I block the ride side air filter intake the bike starts decreasing in revs and shuts off.

Tried to move the bike but it had no power.

Both spark plugs were black(burning a bit of oil and they are not new)

What should I try next? I don't seem to come up with anything that could help anymore. Seems like the air is somehow just going through the slide. Also I find it hard to believe that this could be caused by changing the jets considering they bike has ran just fine on 90s before.