Hi, first post here on HT. I've got a craftsman lawnmower -- 10hp 5 speed. The problems I am experiencing are:

Starter spins but engine doesn't start
Backfires through the carburetor

If you guys could point me in the right direction to some guides on fixing these problems or just help me narrow down what it is that would be great. I've never worked on small engines besides my old go-kart but that's was a good while ago, hah.

TIA,

-Tom

Model number off of the engine would help, but the first thing to try is a new spark plug and make sure the fuel you are using is fresh.

Model Number: 502.254172A

I also noticed that it bogs down for a half second sometimes and then I smell gas directly afterwards. I'll check spark plugs in a bit here. What should I be looking for?
Didn't want to double post so here's my edit:


Checked the spark plug. The gap area greyish and the rest of everything is a black. Not sure about that but I'm sure it can help you guys help me. :) TIA

A sooty black spark plug usually indicates a "rich" running condition. Either too much fuel or not enough air, a dirty air filter can make an engine run "rich".

Install a new spark plug and see if the running improves and the backfiring stops.

New spark plug / air filter did it well. Thanks a million 30yearTech!