4AGE - Engine Smoke and Smell

[jondee86]

(04-19-2017 11:51 AM)pack Wrote:  ...when the problem is stem seals COLD start usually makes a big puff of oil.

That's what I would have expected with old school mineral oils. However,
I'm not sure that modern synthetic oils are as easy to burn. When I ran
synthetic 2-stroke oil in my dirtbike, I noticed that there was much less
smoke and that a lot of liquid oil got blown out the end of the pipe.

But getting a puff of smoke when starting a warm engine is still a good
indication of leaking stem seals.

Smoke when you hit the pedal at the bottom of a long (off the pedal and
in gear) downhill says that there is oil accumulating in the combustion
chamber, and that can be from leaking stem seals or worn rings. Decel fuel
cut means there is no combustion on the downhill, so the oil collects until
you light the fire by hitting the gas pedal.

Cheers... jondee86