I had a mower I bought in 2001, took it with me for a few moves. Sometime around 2011 it started sputtering and just take running like crap. Tried to drain it, and it basically took so afternoon. But I got it drained and replaced. The filter had disintegrated.
With the electric mower, I've had it since 2013 or so. The battery is finally starting to show its age but it does still work well enough. Still haven't done anything to it. Might replace the blade soon