Small Engines (Lawn Mowers, etc.): Troy-Bilt Squall 2100 Snow Blower

Question
QUESTION: 5 years old.  Started up the other day before a winter storm.  Unit started and ran great for about 20 seconds or so.  Then, the engine began to run very rough and smoke profusely.  I shut off and let it sit for a while.  Restarted and it did the same thing.  
While looking at it today, I removed the hose from it's connection point at the valve cover.  Started the engine and it ran fine.  After about 20 seconds, oil (I assume it was oil) began to spew from the hose fitting on the valve cover creating a mess underneath the unit.  But, this time the engine continued to run fine with no smoke.  What is going on?  Thanks

ANSWER: Is there gas in the oil?  Is the oil level too high?  Is the oil thin and running?  Does the oil smell like gasoline?

Was was the last time the engine oil was changed?

Is you model number Troy-Bilt 31AS2T5F711?

Do you have the MTD 270-JU Engine (Zong) engine?

Let me know about the oil.
Eric

---------- FOLLOW-UP ----------

QUESTION: I put a container under the valve cover and caught some of the oil.  It did smell somewhat like gas.  The crankcase was not overfilled.  It probably has been 2 - 3 years since I last changed the oil (haven't had to use the unit a lot except for last winter)  the oil that came out was pretty thin.

No, the model is 31AM2P5B711 (2009)
Engine is a Troy-bilt 752Z270-SU208cc

Thanks for your help and the quick response.

ANSWER: The most common problem we have is gas leaks past the carburetor and into the engine crankcase thinning the oil.  The leak is due to a dirty or old inlet needle seat coupled with little use.

I would start by changing the oil and re-filling with new oil.

Do you have a valve on the fuel tank or carb to turn off the fuel when you are not using the blower?

Eric

---------- FOLLOW-UP ----------

QUESTION: No, there's no fuel shutoff @ the fuel tank or carb.

I will change the oil

Thanks again

Answer
The next time you add fuel to the fuel tank pay attention to the level in the fuel tank.  If the fuel level is much lower the next time you use the blower then the carb maybe leaking.  A pressure test using a small pressure tester will tell you for sure if the carb is leaking or not.

Eric