74bs smoking on startup

[Steve K.]

"After sitting for a couple we

"After sitting for a couple weeks both my 7.4 carb engines bellow white smoke at startup, seems about the time chokes open the smoke clears and everything runs great. Doesn't seem to use much oil. Could choke setting do this? I rarely use the boat, maybe 5 hours in 5 years. I've seen older cars that puff from worn valve seals but this is a real mosquito fogger. Could valve seals have that much impact? PCV valves?"

 

[guyjg]

"You didn't provide the ye

"You didn't provide the year of the engines. Check the spark plugs on each engine. If they are black w/soot then your chokes are too rich. If they are oil fouled, then valve seals could be an issue.

"engines bellow white smoke at startup"

White smoke; does it smell like burning oil? White smoke usually indicates water vapor in the exhaust stream. Cold cooling water entering a hot exhaust stream of a cold engine can cause the "white smoke" until the engine begins to reach operating temp."

 

[fasteddy]

"I think guy's got it. Oil

"I think guy's got it. Oil smoke is gray-blueish. I think ic engines with chokes smoke (fog) more on start up because of more carbon particles in the exhaust from the rich mixture.

Could also be puddled water in the exhaust boiling off in the exhaust heat, OR it could be a blown head gasket. Any misfire issues or bumpy turnover on first startup?"