I have yamaha 225 4 strokes. The motors were slight tilted up for a period of time. I lowered them one evening to change oil the next morning and when I came back, one motor had leaked quite a bit of oil and there was gas present in the oil. Any suggestions?
If you are sure it is engine oil, remove the gearcase and see if engine oil is dripping down the driveshaft. If so, the crankshaft rusted at the oil pump seal and the powerhead has to be removed to place a "speedy-sleeve" over the corroded crankshaft.
See a Yamaha dealer as they are familiar with the problem and have the service bulletin showing how to fix it.