Odd 1997 FZ400 running issue.

[unfazed]

Drain the carbs as it sounds like water in the bowls. At night the water sinks to the bottom and it is picked up by the pilot jets when trying to start first thing in the morning and as we all know water does not ignite to well. Might be worthwhile next time the tank goes on reserve remove it and drain all the fuel from it and refill it with fresh fuel.
Unfortunately the 400 does not have a prime in the fuel tap making the draining the carbs a little more difficult.