In the manual it says to change the oil for winter storage. Why is it necessary to do it for the storage period if the oil is just going to sit. Can I change the oil before I put it back in the water next summer? Also I have a second question can someone tell me where to spray the fogging oil on this machine I only owned 2 stroke carb jetskis and it was so simple. I just dont know my way around this 4 stroke SC engine. Thanks in advance for any input.