I've been fiddling with needles and the mixture screw under my HS4 carby
ever since I fitted my stage 1 kit. I think I've found a good needle but I
can't tell whether the overall carburation is lean or rich. I fitted new
spark plugs today, slightly "colder" than the standard ones and after
overhauling the carb I went for a 5 mile test drive on country roads. After
that I checked the spark plugs and to my surprise the electrode and
surrounding metal were black and dry, but the ceramic element was totally
white. A big question mark appeared above my head... rich or lean? The dry
black deposits suggested rich, but the white ceramic told a different story.
Another question: what oil in the dashpot damper? the haynes manual says
engine oil, so I used 10W40, is this right?

Thanks

Dantiri