Help!!! Shifting issue after swapping Piston Rings and Gaskets

Well i bought an old XJ 750 Seca 82' as a project. I've never worked on an engine before nor ever driven a Motorcycle but i thought if i service it myself, i will ride it. I took the engine apart up to the cylinders head, changed the Piston rings and the gaskets. Checked the compressions, the clearances (changed 3 shims), changed oil and filter etc. Long story short I got the engine running and it sounds great and exactly the same as my friends working XJ 750 when working in Neutral.

But as soon as i switch to the first gear and let go of the clutch a little bit the engine starts making scratching noises. The more i let the clutch loose the louder scratching noise, until the engine shuts off abruptly. I can switch back to Neutral but the same thing happened the second time. I didn't continue trying didn't want to damage anything so i stopped.

I am at loss, I have no idea of what could be wrong, it feels like the gears are out of synchronisation.

Has someone had the same issue before. How do i fix it ??????

 

hard to tell, could be anything but i'd start by looking into the clutch.
try tying the clutch lever back and spin the back wheel by hand as you shift through the gears.
if the wheel spins in gear and the engine runs in neutral, the clutch is all that's left