I have a 1989 Mazda B2200 that we just put a new motor in about 4000 miles ago. We installed a weber carb. kit and installed a crankcase filter in place of the tube that used to go to the aircleaner. It has started randomly puffing smoke out of the exhaust and is blowing oil out of the Crancase filter? Any suggestions?

Is your PCV working? The filter should be inhaling the air and the PCV should be letting it go into the intake.