My '67B has a standard BLMC B, 1.8 motor with twin SU HS4 carbs & unmodified
head, power & tickover seem fine and in 15K miles I have renewed the Champion
plugs but have not seen the need to balance or retune the carbs.
During a recent short service I noted again that though plugs 1 & 4 are a
healthy mid brown colour, plugs 2&3 are distinctly sooty. The Valvemaster
fuel lubricant I add might be a contributory cause, so I am reluctant to
weaken the mixture, but I have no idea why cylinders 2&3 should apparently
run richer ( or cooler perhaps) than the other two.
Much of my mileage, BTW, is fast open road driving at higher revs.
Any ideas?
Tks
Colin.
///
/// mgs@autox.team.net mailing list
/// (If they are dupes, this trailer may also catch them.)
|