Checking Timing With Timing Light

Timing should be same as static setting (7° BTDC), if not, distributor may be faulty. Make sure idle speed stays at specified RPM. Start engine, remove vacuum advance hose and check for vacuum advance at idle. If advance, it could be due to throttle being opened too wide to maintain idle speed or possibly due to incorrect drilling of vacuum advance port, in this case carburetor must be changed.