For the log: Today my 121 (a 122 with 4 doors and one carb) start uneven. The idle speed travel between 800 and 1200 rpm. Some explosions on the exhaust. On first I suspect problems on some cylinder or a air source on the inlet manifold.

After some tests, I´ve no clue about the source, and come to make a more organized analysis. Oh,Oh, as part of the protocol, I check the spark (hanging the cable from the coil a centimeter over the engine chromed cover)...no spark. The fiber core was boken... I change that cable with a solid copper center one (here available on some old shops), voila! - as a safety measure, I change all ignition cables from distributor to spark plugs also to copper solid center - a bit of very low noise on AM radio, FM radio ok, engine run a lot more smooth than before.

Reading about the ignition, now I know that the original ignition cables on the 121 and 122 was copper solid center...it was a return to origins.

Joaquin
Rojo 121 Amazon
Lima Peru

Original spec was for resistor type spark plugs too.

Good on ya to chase ignition before getting bogged down in fuel!

Mike!

¡Es bueno eso!
Si se necesita alambre, otra cosa no sirve.

¿Sabes cómo se inventó el alambre de cobre?

Parece que dos glaswegos (Escoceses de Glasgow) encontraron un «penny»
(moneda grande de cobre) a la misma vez.
--
George Downs, Bartlesville, Oklahoma, Central US

Ja, ja, ja!, buen chiste...en Perú serian dos Arequipeños (Arequipa is our Scotland).

Joaquin