No. My three have all been castrated (they were done at a young age, they are now 7, 11 and 12) and they still spray at will. It tends to be territorial, if another cat is around. Invest in a good spray to clear the smell - I found Oust Three in One is good. Spray is also very corrosive - mine sprayed up cupboards and on some brass screens, and the stain is is really hard to remove if you don't catch it quickly.
Your Michael still needs "doing" though, he will wander less and not father unexpected kittens.
I bet he's lovely!