The 911S Cast Iron Distributor
This distributor for the Porsche 1966 to 1968 911 S model, is easily recognized by the yellow tag, 0231.159.002
Bosch-0231.159.002-Advance-Curve
0231.159.002 or Yellow Tag Distributor
The yellow tag makes this 6 cylinder cast iron distributor easy to spot. The riveted tags usually black. Bosch did not do colored tags on the other Porsche distributors that we know of. Inside, check if you have the dreaded silicon sliding plate. The plate should be dark phenolic. All 911 cast iron ignition distributors need to have a cap with the small cut out. The cut out allows for the insulating phenolic washer on the thru post. This post is where the points signal goes out to the coil.

Differences in the 0231.159.002
This cast iron 6-cylinder ignition distributor has a different ignition curve than it’s predecessors. The 0231.159.002 fits the Porsche 911S. The 1966 to 1968 911S has a different ignition curve. It starts the curve a little sooner and flattens out at 13° advance, which is 26° engine advance. The insides are different than the other cast iron early distributors. This 0231.159.002 uses two different size weights, that is why it has the counterweight to help smooth it out. The sliding plate has to be trimmed to make up for the large counterweight in this distributor.
Bosch uses 0231-159-002 on the tag but Porsche has its own number for the Yellow Tag. The Porsche number is 901.602.021.ZX. On occasion, we have seen a black tag, same number, same distributor, just a black tag. If you have a Porsche 911S from 1966 to 1968, take a look under the lid. See if you have this elusive yellow tag.