Why does V165 have two different MEAs over the same route section?
The most likely reason is terrain. Here's what the VFR sectional looks like:



You can see that the terrain rises sharply to over 3000' close to WINLO intersection, which is too high to provide IFR obstacle clearance (1000', or 2000' over mountainous areas) at an MEA of 4000'. An aircraft flying south on V165 would need to be well above the terrain before reaching WINLO, whereas one flying north from WINLO can use a lower altitude.