[seplo2]

I have a 3100 50 chevy truck with a 216 engine. I am just starting to restore the truck. What causes the sparkplugs to be completely coated with black and black spatter to be emitted out the exhaust pipe?

[va4cqd]

very rich mixture

[poncho62]

Are you driving the truck or is it just sitting and being run occasionally and just idled when it is?

If thats the case, it could be that the plugs are fouling, bad gas, carb getting plugged up........

[matt167]

running rich. fuel distrobution on a 216 really isn't great ( exhaust heated manifold ) so when there colder, they will run a little rich, and having an older carb that probably needs a rebuild won't atomize the fuel as 1 that has been rebuilt

[QParker]

could be really old gas containing lead where the lead has settled to the bottom so you're burning more lead than fuel. Does it rev up (above around 2500) if so it's not the lead, listen to the other guys...

[cobalt327]

Originally Posted by seplo2

I have a 3100 50 chevy truck with a 216 engine. I am just starting to restore the truck. What causes the sparkplugs to be completely coated with black and black spatter to be emitted out the exhaust pipe?

Black is carbon. Carbon is most often formed in an engine's combustion chamber (and therefore on the plugs) because of incomplete burning of the air/fuel mixture. This can be because of a lot of things, but usually will be a too-rich a/f mixture caused by a bad or incorrectly adjusted carb and/or choke.

The black spatter from the exhaust system is this same carbon being ejected along w/either fuel, coolant or more likely water from condensation that forms in the exhaust system by running the engine below the operating temp.

[LATECH]

yup yup yup... running rich + flooding . Rebuild the carb