Small diameter washers causing bladeplay?

[DAVE_M]

I picked up a Boker S2 last year as a project knife. The blade is massive compared to the handle and it would be fun to hack up. Everything about the knife is surprisingly well done (for a $40 knife), but the blade has side to side play when closed. I have to tighten the pivot down a good bit to get rid of the open blade play. I'm thinking about ordering some Phosphor Bronze washers that are a tad larger in diameter, to solve this problem and to get rid of the rough flipping action.

Could the washers be the reason for the blade play or is it something else?