Pressure washer engine ceases to start

It worked great when I got it so I invested in a new hose and wand. No issues putting it on and even using it until I ran out of gas. I got some gas and tried to start it but it seemed locked up. Pulled the plug and it turns great. Put the plug back in and it turns once or twice but then the pull rope kicks back - hard. What could have happened? It's a Briggs and Stratton cheapo so I don't see how it could have gotten out of timing so abruptly but that's what it feels like. It tries to break your fingers if you are holding tight to the rope when it says "nope". That's right. At things stand now, it has developed a personality ... and not a nice one.
If you need pictures and numbers, I can get those easily but this may be a generic small engine question at this point.