- Sun Sep 16, 2018 4:56 pm
#79188
In all probability (as you don't mention which make or model) that oil has just been passed through the big end in order to lubricate it, oil pumped to the big end collects in the bottom of the sump and gets sent on its way by the scavenge pump.
If the piston is left at TDC whenever the bike is not in use so the big end sits above the oil level in the tank and you still have oil appearing then it's time to investigate further
Unwanted additional oil usually finds its way into the sump via the timing shaft or in rare occasions a leaky crankcase joint between the sump and the oil tank or even the drive shaft oil seal.
