Small Engines (Lawn Mowers, etc.): Smoke Engine, blown head gasket, craftsman lawn tractor

Question
Hi John! How are you??? I have a Craftsman lawn tractor model # 917.256510 with B&S engine 15.5HP OHV model 208N707 type 0171 01 code 9510274B that has a lot of white and black smoke came out of the muffler. I keep my tractor garage but during a remodeling project, i left the tractor outside one week and it was a rainning week. After bring tractor inside and start it, it has a lot of white smoke. I suspected that there're water in the fuel and drain out the gas and clean out the carburetor for water ( The carburetor was very clean ). When i put the carb back, the float needle didn't shut and fuel start flooding the crackcase thru the breather hose. I drained and change the oil 2 times to get all the fuel out of the crankcase, reclean the carb by spray all the valve and holes in the carb with carb and choke cleaner.It now has new spark plug, fuel filter, air filter, breather gasket, and i also change the oil and clean the carburetor. The oil is filled to the dipstick level. I let the engine run without the air filter and saw smoke came out of the breather hose that run into the air filter and some smoke came out of the choke valve. The smoke smell like gas and get worse when i try to engage the cutting blade and put some load to it. People at the local small engine shop suggested that i have bad piston rings and i also read in this forum that could be a blown head gasket. I never fix any internal engine parts before but i will get a B&S repair manual and a carburetor rebuit kit tomorrow. Please help me to fix the problems. Thanks John

Answer
Hello David:

I am Doing Fine. Hope this Email Finds you the Same. Did you Clean the Crankcase Breather/Vent when the Crankcase Became Overfilled with Contaminated Oil? If Not, then the Crankcase Vent Will Still Have Oil in it and Cause the Engine to Smoke. You can View a Breakdown/IPL of this Engine at this Site Addy, http://www.outdoordistributors.com/ and Select the B. Then Select Briggs and Stratton. Then Select Don't have Part Numbers. Then Select the File # 28. Then Select the Folder # 28N700. The Crankcase Breather/Vent is Shown on Page 2 of 18 and is Breakdown/IPL # 8. Once you See the Breakdown/IPL, you can See it is a Simple Process to Replace the Head Gasket. Rempve the Valve Cover. Remove the Rocker Arm Assemblies and then Remove the Cylinder Head. Replace the Old Head Gasket and Re-Bolt the Head to the Block. Replace the Rocker Arm Assemblies. Set the Piston to TDC and then Set the Valve Clearance (Distance Between the Rocker Arm and The Valve Stem Top) to the Following: Intake .003in - .005in and the Exhaust .008in - .010in. Then Replace the Valve Cover. Hope this Helps. I am Here if You Require More Assistance. Let me Know What Happens, Please. Thanks.

Good Luck

Respectfully

John