PIddling about at low speed carbons things up pretty badly on a 601,
and a full throttle run will blow out all the loose stuff, pretty
spectacular if it's been a while. Most of it is probably loose soot in
the exhaust.
My personal "tonic" these days is some contaminated fuel I add a quart
or so of per tank -- one of my colleague's wife filled her car up with
diesel fuel a couple years ago, so he was stuck with the ten gallons or
so of gasoline with diesel in it. Not enough to prevent the car from
running (poorly!), and it burns in the lawn mowers, but not well
(carbon fouls the plugs, smokes). A bit in a full tank of fuel and the
300D just purrs!
Peter
