Doing a tune-up on my 223 and the timing marks don't jive with a smooth running motor. With timing light, I see the 6 degree mark about two inches off the pointer. Twist the distributor to align the marks and the engine barely stumbles along at a few hundred RPM's or it just dies. I checked for a vacuum leak around the carb and intake manifold - no problems there. Runs fine as can be with the timing mark two inches below the pointer. I've searched the forum over but to no avail so who has an idea?

Many thanks in advance !

 

Not sure, but some front pulleys / harmonic balancers are a two piece construction with a rubber insert; sometimes the outer ring can slip. Set the timing where it climbs a steep hill best and forget about it.

“But being wrong sure keeps me humble”

 

If the harmonic balancer is coming apart, it won't stop, and sooner or later, the outer pulley will completely walk away from the inner balancer, and end up in the RADIATOR CORE along with assorted pulleys, belts and what have you.

I've seen this happen numerous times in the past.

The harmonic balancer is made of three parts at the factory:

Outer pulley, inner damper, rubber ring. This ring is installed between the pulley & damper, the three parts are then pressed together to form a one piece assembly.