Changed the oil and filter on my bike last night and noticed the oil filter was hard (harder than usual) to spin off. All of a sudden you could hear air rushing into the filter and then it spun off easily!

I had already drained the pan and had the dipstick off the fill spout.

What would cause a vacuum to build in the oil filter???????????

 

Did you run the motor hot before you drain?

 

Let it sit after the ride home to not get burned while doing the maintenance.