Small Engines (Lawn Mowers, etc.): Murray Mower, dipstick tube, murray mower

Question
I have a 10 yr old Murray with a 14.5 briggs engine. Just recently, the engine starts sputtering and I have discovered that when I remove the air filter that there is alot of oil around the bottom of the filter. It's like the engine is throwing oil up into the filter. When I replace the  air filter with a new one, the sputtering and popping stops. What is causing the oil to go up into the air filter??

Answer
Are you using SAE-30 oil?  Is the valve breather clean.  If the breather does not function properly engine vaccum will be lost causing oil in the air filter.  Also, check the dipstich o-ring on the top of the dipstick and the grommet at the bottom of the dipstick tube.  These tend to leak with age causing a loss of crankcase vaccum.

Let me know what you find.
Eric