Small Engines (Lawn Mowers, etc.): blowing oil, blown head gasket, crankcase oil

Question
QUESTION: I have a john deere with a Kholer command 13 in it.When it runs it blowes all the oil out though the exhaust The engine blows some white smoke but runs good. plug shows some oil on it. but not enouth for a quart and a half.

ANSWER: Hello Pat:

>>If this is an OHV Engine, then it can be 1 of the Following;
A->>The Crankcase is Overfilled and Contaminated with Gas.
>>The Following is an Instruction File I Made for the Gas Contamination of the Crankcase Oil. Any Input Concerning the File is Appreciated.
>>Depending on the Engine Model, Usually the Gas in the Crankcase Oil or White/Blue Smoke is Caused by the Carburetor Float Needle Valve Not Seating Properly and Allowing the Gas to Flood the Carburetor and Engine. Then the Gas Seeps by the Rings and Enters the Crankcase and Contaminates the Crankcase Oil.
>The Smoking is Caused Not Only by the Flooded Crankcase but can be Caused by 1 of the Following; a Bad Diaphragm in the Fuel Pump, a Blown Head Gasket between the Cylinder and Push Tube Galley, the Crankcase Vent Stuck/Frozen/Broken or the Carburetor Flooding the Engine.
>>1- Clean the Carburetor and Replace the Float Needle Valve (and Seat if this Model has One). A-  **Remove, Disassemble and Soak the Carburetor Overnight in Carburetor Cleaner (I Use Gunk). I have Found that Most People can Use a Breakdown/IPL and Disassemble the Carburetor Enough for Proper Cleaning. You Only have to Remove the Bowl (if Applicable), Float Pin (if Applicable), Float (if Applicable)  and Needle Valve and Any Adjustment Screws that Go Into the Carburetor Body. The Welch Plugs Do Not have to be Removed. Then Soak the Carburetor Body and Parts in a 1 Gallon Can of Gunk Carburetor Cleaner Overnight. The Can has a Parts Tray Inside it for the Small Parts. Once the Carburetor and Parts are in the Cleaner, you can Replace the Lid for Safety and to Prevent Accidental Spillage. Then Blow Out the Passages with Compressed Air. Install New Parts if Required.**
>>If the Carburetor Float Needle is Good, then; 2- Block the Outlet Port and Pull a Vacuum on the Fuel Pump. If it Holds Vacuum, then it is Good. If Not, then the Diaphragm is Busted and the Pump Requires Replacing.  If the Fuel Pump is Good, then Check the Crankcase Oil for Gas Contamination.
>>If the Crankcase Oil is Contaminated, then Drain and Refill the Crankcase Oil with Fresh Oil.
3- **If the Mower has a Manual Gas Shut Off Valve:  Check the Manual Cut Off Valve and Make Sure it is Cutting Off the Gas Flow to the Carburetor. A- If Not Stopping the Gas Flow, then Replace the Valve. B- If the Mower Does Not have a Manual Cut Off Valve: Install a Manual Cut Off Valve and Turn Off the Gas Flow when the Engine is Not in Use. These Carburetor Styles Tend to Allow Gas to Seep by the Rubber Tipped Needle Kit or the 2 Pc O-Ring Needle Kit. A I Believe I Said Before, I have Seen a Lot of these Problems and this is the Way I have Found to be Sure the Crankcase Oil Does Not become Contaminated with Gas Again.**
>>4- If the Valve is Good or has Been Installed, then Remove the Cylinder Head. On the OHV Engines the Head gasket will Blow Between the Cylinder and the Push Tube Galley. This Allow Oil to be Sucked Into the Cylinder from the Crankcase and the Extra Oil is Just Enough to Cause the White Smoke.
>>5- Check the Crankcase Breather and Make Sure it is Clean and Operating Properly.
>>6- If the Crankcase Breather Sticks, then Oil is Pulled from the Crankcase into the Carburetor Throat and this Causes the White Smoke.
>>7- If the Crankcase Oil is Good, then Check the Gas Tank Cap and Ensure it is Venting the Tank. If the Gas Cap is Not Venting the Tank, then Pressure Builds in the Tank and the Pressure Pushes Gas by the Carburetor Float Needle Valve and Floods the Engine and Crankcase Oil.
B->>The Head Gasket is Blown between the Cylinder and the Push Tube Galley.
>>Replace the Head Gasket.
>>You can View a Breakdown/IPL of the Engine and Mower at this Site Addy, http://jdpc.deere.com/jdpc/servlet/com.deere.u90490.partscatalog.view.servlets.H and Enter the Model Numbers and Click Find. Then Select your Model from the Search Results Area. Then Select the Sectional File. Then Select the Section of the Mower you Wish to View Online. *You can Drag the View Windows for Better Viewing.*
>>You can View a Breakdown/IPL of this Engine at this Site Addy, http://www.smallenginepartswarehouse.com/parts.asp and Select the Shop Online Parts Look Up. Then Select the Model Tab. Then Select the OEM (Kohler) and Enter the Model and Spec Numbers (). Then Double Click on the Model in the Results Area. Now you can Select the Section of the Engine you Wish to View.
>>If you Hit a Snag or this Does Not Correct the Problem,  I am Here if You Require More Assistance. Hope this Helps. Let me Know What Happens, Please. May the All Mighty Bless You and Yours. Be Safe and Happy. 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 8pm EST (US). My New Day Starts then. Comments and Ratings are Greatly Appreciated. Thanks.

Respectfully

John


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

QUESTION: your answer was a good one, but all the above doesn't apply here. engine had new oil; carb rebuilt.engine ran good but all the new oil was blown out. do you think it could be the reed valve? removed head; gasket was good no scoring in cylinder.

Answer
Hello Again Pat:

>>Since All my Other Suggestions were Previously Performed, then
A->>The Crankcase Breather/Vent Requires Cleaning or Replacing.
B->>The Oil Ring is Broken/Worn and Requires Replacing (this involves an engine Re-Ring).
Send me the Model and Type or Spec Numbers Off the Engine and the Mower Model Numbers, Please. With these I can Locate the Proper Manual and Better Assist you. The Engine Model Numbers May be Stamped Into the Blower Housing (metal engine cover) Above the Spark Plug. The Mower Model Numbers are Usually Located Under the Seat on a Sticker on the Body of the Mower.
>>Thanks.

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 8pm EST (US). My New Day Starts then. Comments and Ratings are Greatly Appreciated. Thanks.

Respectfully

John