I just spent the afternoon adjusting my floats on my new '04 Raptor. I used the clear tube method to get the level right at about the base of the top of the bowl. This didn't seem to work. When I'd rev it in neutral, it would backfire midway through the RPM's so I brought the level slightly above the bowl. That seemed to work. I'm not sure if all Raptors are the same, but mine seems to definitely need to be a little higher. I also had a problem when I'd rev the engine and it wouldn't go right back to idle, so I backed out the right carb screw a quarter turn out, but I'm still not satisfied with the floats, I think I might have to make the level a little higher, I still get a little pop when I rev it in neutral, but I don't notice it at all when riding.

 

Don't try and get it to run good sitting there ( other than idle ) or doing abnormal things like really lugging the engine, consentrate on getting it to run good the way you normally ride it.
You may want to put in 25 pilot jets if you've modded the air box.

 

Should the air box be modified? If so, what's the mod?