Pilot jet: I get the EPA stepped in and they were jetted lean from the get go. Factory carb was a 50.0 pilot and they were leaned down to a 37.5. ****ty cold start and idle issues enter stage right... At least give an option for additional pilot jet sizes. Luckily for the sledding community you have folks like Rec Motors out there making a drill kit to open them up a bit (don't forget to open your air screw a bit too). There are NO stock pilot jets available right now, none, across the country. I find out that Yamaha is offering a 38.9 pilot, but AC is not. I also found a local guy that sourced me a 42.5 and a 47.5 to try. This will fix the cold start, the rough idle, and the bobble on take off.
I ordered Yamaha part # 7CU-E4142-42-A0, which is a #42.5 pilot jet used in the Yamaha generators and readily available. It will solve most of the low end hesitation and cold start issues. I first ordered the pilot jet drill bit kit and it worked on one of my machines, but the drill bit sheared off while drilling out the second machine's pilot jet.