I have been noticing puffs of white smoke and obvious distress of the power of the Briggs and Stratton on my Toro engine as the oil is sucked into the engine on a bend or slope, it lasts for a couple of seconds and clears up. I did a check on the oil level and found it to be too high. Odd that, as it was okay in the summer. Just tried again today (the grass needs a cut despite being January) after not using the mower for a couple of months ( did not drain out the fuel for the winter) and could not start the thing. Huge puffs of white oil filled smoke from the exhaust, but not quite starting. Checked the oil and found it was no longer oil but mostly petrol / oil mix and way too full. Drained out the oil and replaced it and ride on mower started first time with oodles of white smoke burning off for a while. Trip round the garden and all well as far as the engine is concerned. Just need to solve how petrol can transfer directly into the oil sump. There is no stop $!^& on the fuel side so perhaps the float valve has stuck open and petrol has been dripping into the engine and passing the rings. Any ideas?