2004 TTR125 with the same issues as most people, cold-blooded, hard starting, won't idle, etc. So I read the forums and step by step worked my way towards a solution and this is what finally worked for me. A jet kit from Procycle - use the #110 main and the #20 pilot. Three turns out on the pilot air/fuel screw. Cut the top out of the airbox. Cold starting twist the throttle a couple of times before you kick, leave the choke on for a few seconds after it fires up. Totally different bike now. Starts with one kick, idles and throttle response is crisp. Thanks to everyone who posted good information here and I hope my setup will help someone else.

The pilot jet and f/s adjustment are what the carb needs to allow easier starting. Twisting the throttle doesn't do anything because there is no accelerator to squirt a prime charge into the cylinder. Opening the airbox and enlarging the main jet really helps mid/top. Ours likes to be run out of fuel before sitting. If I leave the fuel on and let it sit more than a week it's a bear to start. Not to mention the crap gas leaves goo in the bowl. If I shut the petcock off and run it out of fuel before I park it it always starts in one or two kicks.