The tappet screen is easy. Just remove it and remember which way the spring goes and use some break clean to clean it and install. If this does not do it, I would add some oil. They may have not put enough back in on the oil change or your bike is using some. Its easy to tell how much you have in the oil tank. The oil should be about a 1/4 to 1/2 inch from the bottom of the bend in the tube going to the tank. Bigdog now makes a dipstick for the K9's. May be the same for the choppers. Here's a pic
