hi, ive got a 1992 cbr f2 600 its got 41000 on the clock.i got it in october and has been runnin like a dream.The last few days the bike has been runnin reallywellbut when i turn of the ignition the bike just refuses to turn back on. The electrics are all working but when i hit the starter switch nothing happens...its just dead!i checked the kill switch and the side stand and the gears but nothing happens. However it seems to suddenly work after X amount of time.yesterday it was 2 hours today it was 10minutes.i havent got a clue whats wrong!

 

sounds to me like you have a bad connection somewhere that needs to be cleaned, fixed or something. start at the starter button, work your way back to the battery, or go from the battery to starter button.

 

i had the exact same problem it was the voltage regulator/rectifier.

come tothink of it i did replace my battery too because the bike shopsaid it had enough volts (why the lights work)but not enough amps (wouldnt start the bike).

but i went through 2 batteries then replaced the regulator and havent had a problem since. so i guess the regulator was screwing up the batteries.

 

i had the same problem when i hit the start switch. i replaced the battery .

 

+1 on the regulator rectifier. I had the same symptoms on my NC-30 and my F-3 when the R/R went out.

 

I'm with the R/R mine crapped out with different symptoms. The old ones (without cooling fins) are notoriously bad...at least notorious on this forum. Check and see if it has the cooling fins...it is just under the seat on the right side...as a wiring plugged into it. A good replacement is $90-120, but don't get the el-cheapo $40 version. I have also read to use CPU grease between the R/R and frame to help disipate the heat.

The reason your bike would work after time would be the R/R cooling off...which further supports the R/R diagnosis...

 

Here's a way to test your charging system:
http://cbrworld.net/forums/thread/140473.aspx