Cushman 22 HP Front Line (898804) The engine stalled out while mowing. I noticed fluid leaking from the rear crankcase seal, it was oil diluted with gasoline. Lots of gasoline was in the crankcase. I changed the oil, clean the carburetor (walbro carburetor, not original ), float seems good but there was some dirt in bowl. Added new gas filters. Starts right up, sounds fine running. I let it run for a couple of minutes. Check at the oil at drain, seems to be just oil. Turn it over again and get a major backfire. Let it running at idle for a little while, turn it off and let is sit for a couple of minutes before rechecking oil. Dipstick smells of gas and the oil sample is mixed with gas. I was thinking it has to be the carb. Is there something else I need to look at ? Any thoughts ?