Outdoor Power Equipment (Lawn Mowers, Snow Blowers, Chain Saws and more) Discussions

My recently bought (second hand) Ariens ST504 won't start anymore. It used to be really easy to start. Throttle on 50%, full choke and three pushes on the primer and it would start on one or two pulls. It was the neighbor who drove it the last time so I don't know how it acted last time it ran but the neighbor didn't mention anything until he tried to start it next time.

Anyway, now it won't start no matter what. There's fresh petrol in the tank (maybe a bit too much). I've tried having the lid off the petrol tank when starting but that didn't help. The spark plug gets oily after I tried starting a couple of times and after cleaning it I can get it to *almost* start. A few puffs of pretty black smoke and then it dies. Then, the spark plug is all oily again. I checked that there is a spark and it seems fine. Probably time for a spark plug change but it seems wierd that it died so suddenly, no? 

When pushing the primer, it sounds and smells like fuel gets through but I don't know how to check the fuel line better. I haven't starting taking the covers off to check the eninge more but I was hoping to get some pointers before doing that.

So, any ideas?

/Ola, Sweden