Intermitten Start Problem

[Suzuki-san]

This has started a while back, but the problem is getting worse on my 2001 GZ250.
When going to start it, hot or cold, sometimes it will just crank and crank. Then I would turn off the ignition switch, wait a few seconds, turn it back on, and it would fire right up. However, lately it takes 3-5 attempts turning the ignition switch to get it to fire, and am afraid it will leave me walking some day.
It has good gas, I add carb cleaner ever 3-4 tank fulls, the headlight is bright, it cranks pretty strong so the battery seems OK.
Once it fires up, the bike runs like nothing is wrong.
My first instinct is that it is the ignition switch, but if it was that, would it also not crank? Anyone else heard of this issue?
Does anyone know of any switches on the bike that would kill the ignition but allow the starter to turn?
Also, could the valves create such a problem as well? ...when it does not fire it sounds a bit different, but that could be my imagination.
Any feedback appreciated. Thanks!