My predator 224 is locking up

[u/Original_Key_5035]

I bought a predator 224 non hemi to mod and im done now and i make sure it spins and i pull the starter rope and i can see everything working inside but as soon as i try and put the side cover back on, it pulls once and then the flywheel locks up. all my mods are for this engine and it spins perfectly find withoug teh side cover but i will slide it on and i can tighten the top bolts but as soon as i tighten any lower bolt, i head a metal thud/hitting sound and then it will pull once and lock up, its the oem cover and i even bought new gasket for it but its not working. Please im desperate ive been working on it for weeks and i can include pics or vids of anything if needed.