Black blue smoke on acceleration

[ian w]

If after cruising at 1200 rpm for 9 hours and then giving a burst of revs is it normal to see a burst of dark smoke. I have never had my intercoolers cleaned .Could this cause smoke .When I start the engines and run at 1200 rpm there is virtually no smoke.Ian w 53my

 

[TopHattandTails]

Sounds perfectly normal, although I've never cruised that long at that low of an RPM. Its is my practice to run up the RPM to WOT for a minute or so at the end of an extended cruise just for that purpose. Blow the carbon off the heads and make sure everything is up to temp and good and clean at the end of a cruise. I usually cruise at 1925-1950 and for a duration between 1 to 3 hours. When I throw the hammer down, I don't see any smoke, but I think that is due to the fact that I am running already at a higher RPM that is allowing a fully efficient burn. I'd be worried if the smoke didn't clear up within a few seconds, or it smokes again at lower RPM's. If its a puff of smoke - no problem.