Oil in combustion chamber

[LawnDog]

Hello, I have a Craftsman mower with a Tecumseh motor that is having some issues. My wife brought it back to the garage with a report that she could not pull the start cord. Taking a look at it I can see three standout problems. 1) the combustion chamber has oil in it and you can稚 pull the start cord because of the amount of oil 2) it seems way over filled with oil 3) oil is leaking on the floor under the mower (could be coming from the deck because of issue #2

I tore the thing down and on the inside what I found was that the oil seems to be leaking from the intake valve (either that or it was just so over flooded with oil that it was leaking back out once the head was removed) and second the cylinder wall seems ok but does have some scratches / wear on it. The scratching is not super deep, enough that you can feel it with your finger tip.

So I知 not 100% sure the oil can be coming from around the piston, at least not as much as seems to in there. But if not there then where else can it come from? It looked like it was coming from the valves, but again seems like a lot to me. I thought with as much as was leaking in there it would be obvious where it was coming from but it痴 not. What can I check next, is there some tell tale signs I can follow to figure out where the oil is coming from?

Thanks,
Doug

 

[midnite rider]

These are the symtoms of a flooding carburator. Apparently your carburator float is stuck or not floating and allowing fuel to flow into the combustion chamber thus filling up the engine crankcase and mixing with your oil. You need to disassemble and clean out the carburator and check your float settings and bouyancy. The needle is not seating allowing the fuel to continuously flow. Drain the oil and replace with proper amount of oil when you get the carburator issues repaired.

 

[KennyV]

midnite rider is correct...
That is a common problem and a needle seat & float fix 'usually' fixes it... If you want to be sure never to have this problem again... Install an inline fuel shut off in the line between the fuel tank & carb...
Then all you have to do is remember to turn it off when finished mowing and back on before starting... :smile:KennyV

 

[reynoldston]

The only ways for the oil to go into the combustion chambers and engine not running is if the oil crankcase is over full. One way is as earlier said gas leaking into the oil with a needle valve leaking by. Or someone just over filled it with oil? I had a customer that tipped his mower on its side to work on it and the combustion chamber filled with oil. Other then that if the oil level is right, engine not running, the mower is sitting somewhat level the oil will just sit into the crankcase and not go into the combustion chambers. If the rings or valves guides are bad you will get a lot of smoke when it is running.