Gas in riding mower crankkase

[Southner]

How could gas be entering the crankcase of my Husqvarna 48" riding lawn mower?

Mower is 3 years old and has been running fine up until now. Tried to start it 4 times. Mower would start, run 10/15 seconds and shut off. Upon inspection found gas/oil mixture in the air-intake filter and the crankcase oil diluted with gas. What possible causes are their?

 

[mechanic mark]

Post model, serial, numbers as well as all numbers from engine and engine manufacturer.

Gas in Oil | Mower & Small Engine Repair | Briggs & Stratton FAQ

 

[Truthseeker]

How could gas be entering the crankcase of my Husqvarna 48" riding lawn mower?

Mower is 3 years old and has been running fine up until now. Tried to start it 4 times. Mower would start, run 10/15 seconds and shut off. Upon inspection found gas/oil mixture in the air-intake filter and the crankcase oil diluted with gas. What possible causes are their?

Float/needle valve can get stuck open, allowing gravity feed of gas from fuel tank through carb to cylinders. That could be due to debris in the fuel, or a bad float/needle valve. Clean and inspect the entire fuel system, replace lines/filter as needed, and refill with fresh filtered fuel. Inspect the float/needle valve for repair or replacement. Replace oil and always promptly use fuel cut off valve when the engine is stopped. Hope that works.