Hi I have a Wizard lawn mower with a Briggs & Stratton engine that was ran with low oil I don't know much about engines but when I stripped it the piston arm has sheared at the end I can't see any other damage so my problem is I need to replace the piston but I can't see any no on the piston all I have is the engine model no 289707 type no 1179e code 9904:mad:

That's what you need... the numbers off the shroud...

If there was no damage to the block (and the cylinder walls are good?! ) and not scar'd.. the conrod might be just it, and your fine...

I did the same thing with my murray 12.5 hp (ran it low on oil)
Not trying to scare you or anything, but I busted a rod too, replaced the piston rings, replaced the counterweight connecting link (twice) & still had problems. I got so frustrated with trying to fix it, I went out & bought a used motor that (so far, so good) runs fine.

Even though I could see no major internal damage in the original motor, the block is all aluminum & I think the block became stressed or something. Every time I fixed something internal, I would get it back on the mower... start it, & try to engage the blades or something & something else would break. It would run fine until I put a load on it, like engaging the blades.
Hopefully, you won't have these sorts of problems with yours. Like I said, not trying to scare you or anything, but wanted you to be aware of what might be ahead of you. Best of luck with it.