pressure test the coolant system you will find a blown intake or head gasket
excessive amount of fuel, running too rich.
yes...the lack of air would causes excessive fuel which would cause black smoke.
Black smoke = excessive fuel entering the engine
Black smoke indicates excessive fuel possibly the engine is flooding this would also explain the gurgling.
excessive or unburnt fuel.
Excessive white smoke could mean a bad egr cooler which means it is burning coolant or it could be unburned fuel. You need to check and see what it smells like. Egr coolers are only on newer vehicles.
water
Excessive blow-by from worn rings and valve guides. A faulty or disconnected pcv system.
White Black or Blue ? Excessive white smoke out the tailpipe is a good indicator of coolant being ingested into the engine, usually by a failing intake or head gasket. Excessive black smoke is indicating to much fuel is delivered to the cylinders and the engine cannot burn it all. Excessive blue smoke indicated the engine is burning oil for some reason.
Blue smoke = excessive motor oil. Black smoke = excessive fuel. White smoke = engine coolant
Blue smoke is burning oil.
The main cause of motorbike smoke is when the diesel is being burned and used in the engine. This smoke causes pollution to the environment.