Change the fuel filter, and also listen for the prime when you turn the ignition to postition 2, does it prime as it should ?
I would as a matter of course check the usuall stuff, but also when you get it running get the CO set to 2-2.5% CO.
Has the starting got worse since th CTS was changed ?
What plugs/gaps are you running ?, what coil are you running.
tabetha