I noticed oil dripping/burning on the muffler/exhaust directly below the cover/rocker gasket. Is this generally a cause for the oil leak? Mower runs fine but I get some blue smoke from the oil drip. What is involved/degree of difficulty in replacing this gasket? Is it simply removing the bolts and installing a new gasket? Can a do it yourselfer handle it

Which type of engine: B&S, Kohler, etc... model will help for the engine.

Briggs & Stratton 17.5 hp ohv

Just an Idea , check and make sure your oil level is good . Make sure there's no gas in the oil ,

" model will help for the engine"

just an Idea , check and make sure your oil level is good . make sure theres no gas in the oil ,

Oil may be a tad high and I do smell gas in the oil, not overpowering but it's there.

Gas in the oil, totally drain the crank, flush and then refill with fresh gas. Until you find the cause of the gas leaking into the oil shut off the fuel shut off valve inder the tank. I suspect your needle valve in the carb may not be seating 100% and slowly drips raw fuel 24/7 which finds its way past the piston rings into your oil.

Engine model number - briggs and stratton model number 407577, type number 0283-E1