I too was running a 130 in the secondary carb, but it was popping (flames out the back, past the spark arrestor) so I decided it was too rich. I put the 128 back in, drilled a few more holes in the cover, and it seemed a lot better.
The more I think about this, the more I believe you're trying to compensate for a rich condition by giving it more air i.e., drilling more holes in the airbox. Bet you a buck your float valves are leaking.
just my .02