BUt whilst playing I found another quick fix that needs to be completed.
The LH pinky C# spatula key, when depressed can clunk against the C key, such as this video shows.
http://www.ClarinetPerfection.com/work/repairs/20.avi
We could remove the key and adjust it off the instrument, but then we would also have to reinstall and check clearance. For players this next solution is a quick and fully capable one.
To correct this issue you first want to stabilize the end of the C# key. The reasoning for this is as you work on adjusting the top of the key many times one will give downwards pressure which, when this key pushes against the body, will also tend to push out and away from the body. This could damage the pin actuator. Thus the thumb here holds this key stable. (in the 2nd picture below you don't see my thumb because I'm taking a picture with that hand, but it would be stabilizing this part)
Next, on the top part of the lever I place a finger to use as a fulcrum point and to minimize the pressure I mentioned above.
Keeping your other thumb on the lower part of the key to prevent movement (removed to take this picture as I only have 2 hands) I then slightly pull up on the C# lever to raise it. The finger position in the picture works fine, I normally have my thumb on the fulcrum point and my fingers pushing up, but taking a picture one can't see anything.
Note: Many times the C lever itself is adjusted up, down, inwards or outwards. So take into account any adjustments done to that key too as to how you resolve this clunking issue.
Note2: Sometimes the clunking may be due to The C# lever "scraping" against the B lever. And this can occur at the touch area or even on the bottom side of the key.
searching for "clinking" noises just take a little watching on the mechanical aspect of the clarinet and listening skills.
Note3: I have found some instrument cases can actually hold an instrument too tight and push the C# lever IN to hit the B lever.
Note4: sometimes when one depresses ring keys on will hear clunks (to be done later). Always check for ring clipping the side of the tonehole too.
Also if there is movement issues, check for a cork slightly touching the other key while moving. Even though it looks harmless it can create other issues. This of course excludes the entire movement of the mechanism and movement issues of the key rod going through the key itself.