I'm not sure if the Badger 200 is a single action diffuser or a single action needle in body so.....
*Check your air supply. If its canned try a new can, if its a compressor check your pressure output. To spatter on purpose you lower the air pressure, so your pressure may be too low.
*Be sure that everything is attached/connected/secured.
*Is the head damaged or dirty?
*Paint thinned? Too rich a mixture and the drying agents will cause the paint to dry in the head or on the tip or needle. Air passing through as the propellant will accelerate the drying agent and a build up will occur. This can cause splatter. Thin the paint out or use a retarder or airbrush medium. This is dependent on paint so use accordingly.
*Paint clean?
*Check for leaks. (Again)
*If your splatters are showing up as caterpillars your too close to the surface and spraying too much.
*Remember you just replaced the head, so it will not act like the one you've been using for the last 5 years. It is newer and probobly not as forgiving. The action will be a little sharper and if you release the trigger too fast the lever returns too quickly and cuts off your paint supply but leaves some in the head from the previous stroke. it might cause a splatter.
*Is there dried paint on the tip or needle?
*Is there residue in the cup that would cause spitting?
*Air feed clogged? (This can happen if you remove the tip while there is still paint in the cup or brush)
*Moisture in the air feed? Moisture from the compressor? The CO2 can went liquid on you? (Try keeping the can in a warm water bath. Key here being just warmer than room temperature. Not hot.) Moisture build up in the line. Moisture build up in the diaphragm.
*Diaphragm is damaged. This could be from when "you"fixed it or it's just plain worn out. Sometimes paint can get back into the diaphragm and damage it. (This is a factory job)
If all else fails, consider two factors.
1) what is the frustration worth, does it outweigh the downtime incurred by sending the brush off to badger for repair or check-out?
2) Does the frustration and your frugality outweigh MikeV's suggestion of upgrading your airbrush? In this case I would upgrade my airbrush, send the other one off to badger for check-out and you'll have two airbrushes one for either back-up or different applications.
Good luck,
Mike