It is nothing to do with the Fuel injection or carb issue, whatever setting you tries, the C2 will run hotter than the C1 and it is to do with the 270 crank. I have had it with a TRX850 and the now with the 900.
Is quite clear from the uneven discoloring of the two header pipes and I had a laser temperature gauge pointed at the headers that quite clearly shown this.
OK. so what did your laser temp' gauge tell you the temperatures for C1 & C2 were? I for one am interested to know.
BTW, so far both my header pipes look identical in colour, but she only has 3000k on the clock. C1=14 C2=16