Originally Posted by neptunesjester
From my own experience, my diesels have emitted black smoke from these causes:
1) initially over propped during refit
2) fouled bottom, prop
3) overloading the motors.
When the injector pump
and injectors needed rebuilding, i had grey smoke and noticed unburnt fuel in the exhaust
I think overloading the engine
is the most common cause. I have also seen where a faulty injector can cause black smoke and also result in excessive cylinder wear, like adjacent cylinders with several thousandths wear and the affected cylinder with fifteen. The owner bought a new short block, that is the engine
minus the head
and accessories. I thought he should have rebuilt it.
If you are getting smoke of any kind after warmup, investigate to avoid spending money
needlessly, or having the engine quit.