Small Engines (Lawn Mowers, etc.): Toro Model 20016 6.5 hp - white smoke from muffler, crankcase oil, gas seeps

Question
QUESTION: I have a 4year old Toro model 20016 with the Tecumseh 6.5 model LEV120-362003A engine. I started to mow my lawn the other day and a large amount of white smoke started to come out of the muffler. It only seemed to do this while under a load or being slightly tilted. I have read your earlier posts stating the head gasket could be the culprit - I removed the cylinder head and made note of the gaskets condition and didnt notice anything horribly wrong with it. I also removed the carb and disassembled it - noting it was suprisingly clean. While removing the spark plug I noted that half of the insulator was missing and I presume was particulated through the engine. Since I have it "half-way" apart should I look at the rings as the culprit?  I maintain this mower religiously and the only other recent change was my oil from standard 30 to Amsoil Formula 4-Stroke 10W-30/SAE 30 Synthetic Small Engine Oil.  I have no problem "going all the way" with the engine rebuild but wanted to know if you thought it was really necessary.
Thank you.

ANSWER: Hello Steve:

Check the Crankcase Oil for Gas Contamination and for Being Overfilled. Usually the White Smoke is a Sign of the Crankcase Oil Being Contaminated if the Head Gasket is Not the Cause. The Carburetor Needle Valve Allows Gas to Leak into the Carburetor and Flood the Cylinder when the Engine is Not in Use. Then the Gas Seeps By the Rings Into the Crankcase. This Overfills and Contaminates the Crankcase Oil and Causes the White Smoke. Hope this Helps. I am Here if You Require More Assistance. Let me Know What Happens, Please. Thanks.

Good Luck

Respectfully

John

PS: I am Allowed to Answer 10 Questions a Day. If you See I am Maxxed Out, then Try Submitting your Question at or Just After 9pm EST (US). My New Day Starts then. Thanks.

Respectfully

John

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

QUESTION: Drained oil from bottom drain plug - let sit for several hours to see if there was any seperation. Cannot smell or see any gas contamination. Oil looks pretty clean as it was changed about a month ago. Valves look ok, seating properly and have only a small amount of build up on them. I did notice some oil in the air filter - had to look inside it as it was not soaked into the paper itself.

Answer
Hello Again Steve:

It is Rare for a ring to Crack of Break this Early in the Engine Unless it is Being Used Every Day. If the Oil is Not Contaminated and the Crankcase Breather is Not Saturated with Oil, then Either the Crankcase Breather is Not Operating Correctly and Needs to be Replaced or there is a Bad Ring. Usually if it is a Ring, the Breather will be Saturated because the Compression is so Great it Causes the Breather to Allow Oil from the Crankcase to be Sucked Into the Carburetor and Causes the Smoke. If the Breather is Bad, Usually the Sudden Increase in Torque or a Slight Incline will Cause the Breather to Draw a Lesser Amount of Oil and Smoke. You can View a Breakdown/IPL of the Mower at this Site Addy, https://lookup3.toro.com/partdex/default.cfm and Select Start Parts Viewer. Now Enter the Model Numbers. Now Select View Assembly Drawings. Hope this Helps. I am Here if You Require More Assistance. Let me Know What Happens, Please. Thanks.

Good Luck

Respectfully

John