Hello all,
Decided to try some more work on some lawnmowers. I got one from a guy and it was in rough shape. Troybilt 12AV834Q711
I was able to get it to startup, but it makes this tapping noise while running. Is this the valves knocking? I set the valve lash to specs and didn't really notice anything when I had the valve cover off. https://www.youtube.com/watch?v=ZE5Dy1XoyAE
I had a GCV160 that made a tap/rattle noise after about 7 yrs. of regular use on a Husq. mower. I ran it like that for about another year before I gave it to a friend who used it for a year or so more before ... well, that's another story. Anyway, for me the noise was a bit annoying but did not affect performance.
Since you say that the motor is not something you have to get fixed right away, you might want to disassemble it & check things out. I used a series of videos to do that & replace rings on a GCV160 that smoked. It was fun & it now works fine. The link below is for the first video & you can access the others from there.