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

Question
I was looking over the answers you were giving a recent person about his briggs 14.5 hp mower blowing smoke. I have a troybilt mower with a 17hp i/c motor in it. I beleive it is the same motor. anyway it looks just like the 14.5 hp. mine is doing the same thing. when idiling it is ok. when i rev engine to engage mower blade it runs for some time then bellows out white smoke ....enouph to create a cloud on the whole street. if i idle down it stops almost immeadiatly. one thing mine does have where the other person said he didnt is....i smell gas in the oil...and alot of it. it smells like 25% gas. some other forums indicate it could be a fuel pump....what is your sugestion? the mower is only 1 year old...not worked hard.

Answer
Hello Brian:

The Problem you Described can be Caused by; 1- A Blown Head Gasket between the Cylinder and the Push Tube Galley. Replace the Head Gasket and Properly Torque the Head Bolts and Reset the OH Valve Clearance Properly. 2- The Carburetor Float Needle Valve Not Seating Properly and Flooding the Cylinder and Crankcase with Gas when the Engine is Not in Operation. Is the Crankcase Oil Contaminated with Gas? If yes, then Install a Manual Cut Off Valve and Turn the Gas Flow Off when Not in Use. Also  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, Float Pin, Float 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. 3- The Vaccum Fuel Pump will Rarely Cause this Problem. Usually the Fuel Pump will Stop Operating and No Gas Gets to the Pump or the Engine to Cause this Problem. 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. From your Description, it can be Either the Head Gasket or the Carburetor. 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 (first 4 digits Only). 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. 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