1 min read

Why is Fuel Mixing with Engine Oil in the Crankcase?

If you notice gas mixed in with your engine oil, you should follow these instructions to address a potential fuel leak in your lawn mower, snow blower or outdoor power equipment.

What causes fuel to leak into my engine oil?

  • The fuel shut-off valve isn’t closed properly.
  • Fuel float in the carburetor being stuck in the open position due to gumming (caused by stale fuel) or debris.

How do I fix fuel leaking into my engine oil?

  • If your engine has a fuel shut-off valve, ensure that this valve is closed when the engine is not in use to prevent fuel leaks.
  • If carburetor problems are causing fuel to mix with your oil in the crankcase, you should perform a throughout cleaning. Find out how to clean your small engine carburetor.

For any other specific questions or concerns related to fuel and oil, make sure to contact a Briggs & Stratton Dealer near you.

How do you rebuild or overhaul a small engine carburetor?

4 min read

How do you rebuild or overhaul a small engine carburetor?

Rebuilding the carburetor may be required if basic adjustments don’t fix your small engine problems or improve performance on your lawn mower or...

Read More
How do I troubleshoot & repair common small engine problems?

4 min read

How do I troubleshoot & repair common small engine problems?

Having engine problems? Use this comprehensive guide when troubleshooting issues with your lawn mower, snow blower or other outdoor power products...

Read More

1 min read

Why Does My Engine Backfire or Afterfire?

Is the small engine on your lawn mower, snow blower or outdoor power equipment making loud noises? This FAQ from Briggs & Stratton will help you...

Read More