FWIW...
I have a 63 (not the S model). Idle is 2000 to 2100 RPM. Sig 2c fuel 15% nitro running a 12X7 APC. I'm not having any issues with mine. One spin or twenty spins it never dies. It will idle for 30 seconds or longer and still transition without hesitation, in the air or on the ground. Just flew it on new years day in 32 degree weather. Only change I made was to the high speed mixture.
If your 63 was mine, I would play with the idle mix a bit to see if an improvement could be made. Write down your changes so you can go back to your current settings if no improvement can be found.
Ken