Small Engines (Lawn Mowers, etc.): Kohler Courage on Toro Tractor, toro black smoke

Question
Just under two years ago, I purchased a Toro LX500 to use primarily as a snow blower.  The other day, while snow blowing under load, black smoke began to spew out of the exhaust.  When I cut back the power, it stopped and I continued snow blowing.  But then in a while it did it again, so I stopped.  The next day I was able to snow blow about 20 min before the problem happened again.  I thought it might be the fuel but a clanking noise was also present, I think.  My truly wild guess is that there is some oil seal or something like it in the engine and that the seal is weak.  Under stress it leaks and then reseals when not under stress. Is this possible?  Is the engine still under warranty if less than two years have gone by?  I appreciate any help.

Answer
I imagine what's happening is the air filter is getting clogged with snow.  Black smoke is an indication of an over-rich condition.  This can be caused by the air filter getting clogged up.  This is why most snowblowers don't use airfilters.

Ask around at local small engine shops if this is a common problem and what the local fix is.

Let me know if you have any questions.  Thanks, PK.