Lee Teicheira and Bill Lawrence pulled lower spark plugs and cranked engine to verify that oil pressure was now normal. All good. Pulled plane from hangar and started engine. Engine ran but very roughly. Now appears to be a fuel concern. After researching carburetor, it appears that engine is running lean. Checked Needle valve adjustment and found it to be incorrect. Adjusted needle valve and reinstalled carburetor. Found Throttle cable to have rough operation and sticking. Drained fuel tank and removed tank for access to cable routing through firewall. Removed cable. Ordered new cable.