Carb question

[Merc 2.5]

I'm runnin a modded 2.5 200 with wh22s , motor runs great , but I've read 2.5 run little leaner in mid range with wh carbs ,,, I've also been told by reliable source it's not enough to hurt it but get little better mileage,,, I'm not concerned of burning down cruising mid range but would like to know what happens when I completely remove backdraft jets?

Little richer mid??
Does it affect idle??

[FORBESAUTO]

Removing the backdrafts will richen midrange. The smaller the jet the leaner, the larger richer. Mainly only effects midrange. They lower the pressure in bowls lower than atmospheric pressure. I normally don’t run em.

[Merc 2.5]

I'm gonna pull em and give it a shot soon as all this stupid weather breaks and river is back in its banks,