Small Engines (Lawn Mowers, etc.): mower smoking on start-up, valve stem oil seals, head gasket

Question
QUESTION: Hi, I have a ride-on mower with the 17 HP B&S motor (model 311777; type 0134E1). It smokes badly shortly after start-up and stops smoking after a minute or so.  I was thinking valve stem oil seals, but when I pulled the head I find it only has one.  Does this sound right?  would this be the cause?  I checked the cylinder compression by cracking it on a warm cylinder with the electric starter, and got a reading of 130 psi.  Is this a good reading for this engine, or could the rings be worn enough to produce all that smoke?

Thanks,
Andrew



ANSWER: Hello Andrew:

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 and Type Numbers. Then Double Click on the Model in the Results Area. Now you can Select the Section of the Engine you Wish to View. On the OHV Engines the Head Gasket Can be Blown Between the Cylinder and the Push Tubes, this will Cause the Smoking you Described. A Bad Valve Guide or Valve Seal (Only 1 on this Engine) can Cause the Smoking you Described. The Smoking can Also be Gas Smoke. If the Carburetor is Allowing the Cylinder to Flood when the Engine is Not in Use, this will Happen. Is the Oil Over Filled? Doe the Oil have a Gas Smell to it? 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: Thanks for the quick reply, John.   I have located the IPL, thanks for that.  The smoke in question is definitely blue oil smoke, not gas smoke.  The oil level is correct.  The head gasket has a suspect-looking part in the area you mentioned - part of the coating between the mating surface and the steel part of the gasket looks blown out leaving a definite gap, so I'm thinking that's a probable cause.  I'm getting the valve guides and seal replaced anyway seeing's as it's already pulled apart.
You didn't comment on my compression reading??  There are minute amounts of oil seeping past the rings in the three days it has sat there, but not so much that I would suspect that to be the cause.  I was hoping that a good compression reading would eliminate excessive ring end gap as part of the problem.

Regards
Andrew

Answer
Hello Again Andrew:

The 130 Compression is Good and it Does Eleminate the Compression Rings but Not the Oil Rings. The Description of the Head Gasket seems to Indicate the Head Gasket is the Cause of the Smoke. Keep me  Informed, Please. Thanks.

Respectfully

John