I have a troy bilt super bronco rider. I bought it used last year for $350 and it ran great all last summer. Recently It has developed an oil leak. Oil is pooling ontop of the Valve Cover. Is this a gasket issue? Oil seems to be dripping off and causing some white smoke when I was mowing today. Engine had a crack in the block the previous owner had it welded and it hasn't caused a problem since. I change oil and filters regularly and take good care of it.
Engine seems to run strong but when it smokes it becomes an annoyance. See the photo below. You can see the oil just sitting atop the valve cover.

Engine seems to run strong but when it smokes it becomes an annoyance. See the photo below. You can see the oil just sitting atop the valve cover.
