Why is gas in the oil - Cub Cadet SLT1054 54 in. 26 HP Kohler V-Twin Hydrostatic Front-Engine Riding Mower

First how much oil..a little is caused by worn rings etc...but if you are talking a lot..then your carb float is sticking allowing the gas from the tank to continue to flow when the engine is not running..this is due to the electrical positive shut off switch at the bottom of the carb bowl..trying to stop gas from flowing out on tne ground when the float sticks..unfortunately by design when this happens the gas will find its way through the intake,into tne cylinder and into the crankcase..sometimes filling it and the cylinders..you can replace the valve...but WILL happen again due to the design of the valve..my fix that works 100% ..IF YOUR MOWER HAS ONE make sure you shut off the gas valve EVERY TIME YOU SHUT THE ENGINE OFF as it does not take long to get into the engine.NOTE to eliminate any gas left in the carb getting into the engine..I run the engine about a min AFTER SHUTTING OFF TNE GAS SHUT OFF VALVE.. If you do not have one put one in some where between the tank and the carb where you can easly get at it..just remember every time...fixed mine and a couple other without one more gas in the oil..OH AND MAKE SURE YOU CHANGE THE OIL,FILTER AND CLEAN THE PLUGS AND CYLINDERS..Good luck.

When the cylinder intake valve opens on the downstroke a fuel and air mixture is pulled in. Then when the piston is about to go up the valve closes. As the piston continues its upward journey the fuel/air mixture is compressed until at the top the mixture is ignited pushing the piston down. Compression is achieved by keeping a good seating of the valve and the compression rings on the piston. These rings move along the cylinder walls and are lubricated with the engine oil. As these rings and/or valves wear then they "leak" or lose compression. It seems the rings have lost sufficient seating to allow some of the fuel/air mixture to bypass them.