A hot CDI box doesn't mean it's failed. But if upon checking all the ignition connections there's a signal to the CDI but no spark (check both cylinders) then it could be the CDI.
I had mine fail when I first got the bike, on 3 different occasions. Eventually I traced it to the wiring harness having been modified by the previous owner to place the CDI in a different location to standard. He'd used crimp connectors, but this allowed a spark to occasionally travel between two connections and fried the CDI.
So I soldered and shrink wrapped each of (8 if I remember correctly?) the wires, then wrapped all together with insulating tape. Never had a problem again.
I have a brand new unused CDI I used to carry as a spare in case mine broke again, but knowing it's fixed for good, I could sell it to you if you need an SP2 one for what it cost me, which cost me less in Japan than what it'll be new in the U.S. now I expect.
Euro RC51 SP2: HRC WSB Ti Hi-Level, T1 Airbox & Snorkel, PCIII, Dymag CA5 Carbon Wheels, Ti64 Spindles (F, R & Swing Arm), Mori Link, Maxton GP7 Shock & Ohlins 832 Forks, Brembo GP Calipers & SBK narrow track (F), Braketech Disc (R), Brembo billet Underslung x 2 Brembo RCS, Tyga Triple, 7075 Stem, Probolt Titanium all over, Babyface rearsets, MR Complete Carbon Lineup, Custom Undertail & CBR 1000 LED, Watsen LED Indicators, Harris Brace, Giles clip-ons, Corbin seat, etc. 2013 BOTY.