First Biscuit

[Daz Gizmo]

The cut is 4.23 according to my digital calipers.  I think the problem is the router (a good workman doesn't buy cheap tools), it's not entirely square to the base plate.  I'll try wetting sounds like a good solution....

Yes, if the router base is not square to the spindle you will be getting a wider cut... try applying some masking tape layers to the router base to true it up.