I have a Yard Machine push mower purchased new from home depot about 1.5 years ago. I keep it well oiled and it get used about once a week. Lately it's been working at about 75% and upon the first pull, black smoke comes out of the exhaust. I put new oil in a few weeks ago but not sure if that's the probably. Does it need a tune up or something else?

Thanks,
TJ

Going with the obvious, sound like you put tooo much oil in it. Read the manual. Its time to replace it anyway. Get fresh clean oil in there
Frank

Yeah I might have put too much oil in there. I think it was about half a bottle. Maybe I'll drain it all and put new oil in there.

Check your air filter it may be oil soaked or just plugged, this will cause a rich run with black smoke and a power drop.

Black smoke is too much gas... white to blue is oil...

DO check the air filter...

The air filter was complete glogged, so I cleaned it thoroughly. I also drained the oil and added new oil because last time oil was added, the old stuff was not removed. Now it works like new. Thanks for the tips.

Ok, now for that air filter... if its paper, replace it (once a year, just like a car, you'll get better performance and less gas usage if you change it regularly) if its foam... and over 2 years old, replace it, make sure to oil foam filters...