Small Engines (Lawn Mowers, etc.): smoke from exhaust, overhead valve engines, blown head gasket


Question
QUESTION: Hi i have a craftsmen 21hp bs motor tracter I hit a big root in yard ever since noticed smoke coming from exhaust and oil is very dirty any Ideas what i screwed up thanks

ANSWER: Hello Leo::

>>Check the Engines Crankcase Breather/Vent for Oil Contamination, a Damaged/Bent/Sheared Flywheel Key and a Blown Head Gasket between the Push Tube Galley and the Compression Chamber.
>>On the OHV Engine these 3 Components will Cause the Smoking Problem you Described and Hitting the Root as you Described will Usually Damaged the Flywheel Key if it Doesn't Damage the Head Gasket.
Is the Crankcase Oil Contaminated with Gas?
>>Send me the Model and Type or Spec Numbers Off the Engine, Please. With these I can Locate the Proper Manual and Better Assist you. The Model Numbers May be Stamped Into the Blower Housing (metal engine cover) Above the Spark Plug or the Muffler. Many horizontal shaft, overhead valve engines have these numbers stamped into the OHV rocker cover. However, on certain overhead valve powered generators, the equipment manufacturer installs a decorative chrome rocker cover OVER the Briggs cover. If your engine has a decorative cover, it may be necessary to remove it in order to locate the Model, Type, and Code. If this is a Briggs and Stratton  Engine, then you can Also Use this Site Addy; http://www.briggsandstratton.com/maint_repair/BS_modeltypecode.pdf for Assistance in Locating the Model, Type and Code Numbers of a Briggs and Stratton Engine.
>>If you Hit a Snag or this Does Not Correct the Problem,  I Hope to be 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 3 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. All Follow up Questions are Accepted at Any Time. Comments and Ratings are Greatly Appreciated. Thanks.

Respectfully

John

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

QUESTION: model 331877 type0805e1 code077ze.pulled plug very sooty black.oil may be contaminated with gas.just changed oil 1wk ago oil fills very light and black

Answer
Hello Leo:

>>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 and Enter the Model (5 or 6 Digits) and Type Numbers. Example: 331877-0805. Then Double Click on the Model in the Results Area. Select Sectional Index. Now you can Select the Section of the Engine you Wish to View.
>>It Sounds like the Crankcase Oil is Contaminated with Gas.
>>A Sudden Stop as you Described will Usually cause Oil to be Pushed into the Crankcase Breather and cause this Problem.
>>The Sudden Stop can Also Blow the Head Gasket at Between the Push Tube Galley and the Compression Chamber causing this Problem.
>>It can Also be the Carburetor Float Needle Valve and the Solenoid may be Sticking and Allowing the Carburetor to Flood the Cylinder and Crankcase when the Engine is Not in Operation.
>>If you Hit a Snag or this Does Not Correct the Problem,  I Hope to be 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 3 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. All Follow up Questions are Accepted at Any Time. Comments and Ratings are Greatly Appreciated. Thanks.

Respectfully

John