Hello, Dave, thank you for reply and advice!
I checked the transmission rollers just in case and they are all going smoothly. I also changed the fuel and vacuum tubes since they might've had cracks somewhere from sitting for 2 years.
What I failed to mention in my original post is that the issue with limited revs only occurred when motor and transmission was warmed up. I could go to the city (~15 km) and on the way there everything was okay - could go full throttle with no rev limit, but on the way back I could only go up to 7000 RPM.
I realized that when installing the new engine I didn't clean out carburetor (although I had plugged all openings before storing it). So I cleaned it and now I have a new problem. When accelerating past 7000ish RPM engine suddenly starts to cut out but this time it dies fully instead of 'restarting' when I close throttle. I can make it run with stuttering for some time by rapidly opening and closing throttle (probably using the little spray pump on carburetor). After letting the bike sit for a minute I can start it again. On center stand there is no such issue - I can rev it up to about 10000 RPM (at least that's what the tachometer shows) easily and engine runs fine.
Could it be a bad carburetor or the rotor/stator assembly? I'm a little lost
