Thanks for the question.
Excess salivation is something which you see in the cat from time to time, before you will have any chance of treating it you will have to come to some form of possible diagnosis as there are quite a few possible causes.
While I cannot diagnose this for you over the internet I can make a list for you of all the possible causes of excess salivation I have personally seen in my years as a vet in practice. What your cat is suffering from will more than likely be on this list, it is possible that your cat in your cat's age group has a viral infection which is causing ulcers in the mouth or it could be a result of something the cat has eaten such as some house plant.
If I wanted to make a list of what would cause excess salivation in the cat it would go something like this :
1. A foreign body like a chicken bone or fish hook stuck in the mouth or throat.
2. Ulcers or wounds in the mouth.
3. Poisons, certain plants in the garden, chemicals from the environment.
4. Infections, bacterial or viral centered in the mouth, throat or salivary gland.
5. Salivary gland defects such as sialoceles.
6. It is very rare but cancers of the mouth and throat are possible.
My advice : You should have your vet check your cat over at the next available routine consultation, it is possible a course of antibiotics may help but in any case you need a diagnosis.
I have to tell you that I have seen a number of cases of excess salivation where I have not been able to determine a cause but they have slowly resolved over a couple of days without intervention or treatment.
Here is a link to a web page which covers this subject so you can research it in depth : LINK
The smell of the urine may or may not be connected as this is very variable in the cat but it could be a factor in certain diseases such as kidney disease.
If I have not covered your question fully enough or you would like to ask more I will be online for the next hour or so and I will be at your disposal.Scott Nimmo BVMS MRCVS