I'm having trouble with what seems like a missfire which is intermittent sometime she will runs smooth for 2o mins then suddenly she will missfire and the engine rocks badly at above and below 2000 rpm, she kicks into four cylinders after 2000rpm but does anyone know below 2000 is she running on just 2 cylinders or is it just shutting down 2 carbs until you go over the 2000 mark. Have changed plugs with no improvement am thinking CDI boxes now or could it be pre ignition timing?????
