Briggs 24 Hp intek engine problem

[maltpj]

Hello,
I was mowing today and when I turned of my mower it backfired 3 times and smoked. Now when I cranked it back up it ran ok at high rpm but a lower rpm it was making a knocking sound and smoking white smoke. I checked the valves and they seem ok, any ideas? The engine only has 44 hours on it. Oil level is good.

 

[cdaigle430]

Sounds like a fuel issue, try fresh gas and clean spark plugs. Also try a little sea foam.