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I bought a new (customer returned) mower from a salvage dealer. It has never cut grass as below the deck is pristine. I added oil and gas and it started on the second pull. It pours smoke from the exhaust as well as spits oil (maybe oil vapor) that gets the deck and wheel oily. I saw one expert said oil in the cyllinder can cause this. Even with a new mower? One other said to let it run for 15 min to burn it off, safe? Any suggestions are welcome. Thanks Tim G
Thanks to the help posts. I removed the muffler and the guard and let the mower run w/o it attached. It run loud but perfect, no oil! no white smoke! When I re-attached the muffler, it spit a little oil but no white smoke. I removed it again and no oil and no smoke. I think the muffler may have had some oil in it and I drained it and a little oil came out and now I am soaking it in gas to remove any remaining oil. I’ll let you know what happens when I re-attach the muffler and re-start. Thanks again to AB, Phillip and Turkey
Sometimes when the mower has accidentally been laid on its side or even turned over, oil can drain into the cylinder. If it runs long enough, the oil will burn off.If it accidentally has a oil/gas mixture, you will have to drain the tank and flush the carb, and change the oil. It is also possible that the rings are broken or worn and letting oil get by the cylinder into the combustion chamber. It would have to be significant in order to throw the oil out of the exhaust. Depending on how your mower runs, it could also be a broken, stuck or burned valve or valve spring. You could do a compression check on it when the engine is cold. that would give you an idea of how bad the cylinder is. Not sure what type of engine you have, same Briggs and Stratton engines utilize a breather valve to control and maintain crankcase vacuum. The breather valve is a fiber disc or reed which closes on the piston up stroke and opens on the piston down stroke. The breather is located on the cylinder or inside the rocker cover, depending on engine model. If the breather is clogged you may develop to much much crankcase vacuum, which can force oil out into the combustion chamber and ultimately out your exhaust. If you can let us know what engine your mower has, we might narrow your problem down a bit. Hope this helps, good luck.
