Disassembled portafilter & now my shots are not calibrated properly.
I disassembled the portafilter to clean it because one of the spouts was not pouring. After I cleaned it and put it back together the spouts now pour properly but the shots have no crema and they're really weak. One contributor here said, "It is impossible to put one of these back together. They can only be assembled by machine. Once you take it apart, its broke; unless you want a non-pressurized porta-filter." Henry H, replied that he had, "disassembled, cleaned/repaire
If you take a look at the pictures in this teardown, the large spring on the top holds a needle valve in place which plugs the portafilter; you can see the tip of it if you remove the filter basket. Once you start the brew cycle, pressure will build up in the brew head until this spring is overcome, at which point the coffee flows past the needle valve at high pressure, creating the crema. If your coffee is flowing very quickly after starting the brew cycle and you're not getting any crema, you may be missing this spring, your needle valve may be broken or the portafilter might not be correctly assembled. Individual parts for this portafilter are difficult to impossible to find, but replacement portafilters can be found at many online retailers; I would try Parts Guru first.
This is a great answer, and the picture goes a long way to show how actually simple and straightforward it is to keep the portafilter clean, instead of the widespread fearmongering and dire warnings that abound most everywhere else online! Two Thumbs Up, Henry H!
Going further, lifting the spring shown in the picture will also lift the needle valve on its hinge (don't worry, it won't fall off, just lift the spring and put it aside, it'll slip right back on no problems). This exposes the valve seat for cleaning and it's then just a matter of using a toothbrush, some Q-tips and a household degreaser such as ammonia (caution, it's fairly corrosive, use dishwashing gloves) or glass cleaner to remove the gunk that may have made the mechanism stick in a partially closed position.
When you do that, just be careful not to do it too forcefully, notice on the picture the little feather spring, how it should be set in, should it come off. I simply put my finger on it while I work with the toothbrush so it won't. In any case, it's very easy to put back on but it's a small part to look for should it fly off ;)
Cleaning the outlet spouts in the handle is just as deceptively simple, also remove the handle end cap to clean the inside of the handle, it's hollow and this is where the pressure release goes in case of need, it may be full of coffee residue as well, just imagine what ugly after taste it could give your coffee...
Total actual cleaning time, not counting soaking (I suggest you let it soak an hour in pure household ammonia in a covered container to soften the gunk), was about 30 minutes, including reassembly and running clear water through it from the machine.
Now brew yourself a fresh coffee and taste the best coffee you've had in a long time, possibly not since the machine was new ;)