Shop Products
Houzz Logo Print
billfaith

overfilled mower with oil

billfaith
12 years ago

I have an older rider with a 12.5 horse Briggs and Stratton engine. I somehow ended up filling it with to much oil to the point it was coming out of the carburetor. I drained the oil and refilled it and now it wont start. I bought a new spark plug and nothing. I sprayed some carb cleaner under the air filter and it starts on this but only runs a couple seconds. What else can I try?

Comments (4)

  • bluemower
    12 years ago

    Since the intake manifold (or breather hose) is located fairly high on the engine, you really put a lot of oil in it. My impression - from your description - is oil is still laying in the intake manifold and the carburetor area. The piston area and muffler may also be flooded. Remove the sparkplug and the air filter for inspection. You might continue trying to start with a small prime of gasoline. If you can get it run, it will flush out the excess oil. I would expect a lot of smoke until the oil is burnt out of the cylinder and the muffler. Keep an eye on the correct oil level. On Briggs, the dipstick must be screwed in all the way when checking oil.

    The other choice is to take the carburetor off for cleaning.

  • billfaith
    Original Author
    12 years ago

    Thanks. I will try to run it on some gas prime tonight and see if it stays running.

  • bill_kapaun
    12 years ago

    Are you sure you overfilled it THAT much?
    Often a bad needle/seat in a carb will allow gasoline to fill the crankcase and raise the oil level.
    SMELL the oil for the presence of gasoline to make sure.

  • rcmoser
    12 years ago

    IMO Priming with gas will probably flood it. Why, it just hard to measure gas small enough to not coat the combustion chamber and spark plug, if you do that then it won't fire till some of the gas evaporates. That's why carb. cleaner works good for priming. It evaporates quickly unless you hold the nozzle down for 5 seconds or more then you will probably have the same condition as dumping gas down it.

    I would first check the oil after it sets over night. as bill suggested it maybe filling up with gas. if not IMO you need to remove the spark plug spray carb. cleaner down the spark plug hole for good 5 seconds. Motor the engine over to wash out any oil residue and any excess carb. cleaner. spray the spark plug and install it. now you got the combustion chamber clear of any oil and primed for starting. If it still starts and dies use carb. cleaner few more times see if it will take off. if not then you may have other problems caused by too much oil building up pressure and pushing some gasket out.

Sponsored