Export thread

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?

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

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

Southner said:

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?

Click to expand...

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.