casipak,
Search this forum (Electric RC Helis) by author for JeffElecRC and look for the thread "E-sky HB2: Brushless HOW TO". It has step by step instructions with pictures of the mods you need to make to the 4-in-1 so that you can use a phoenix-10 ESC for the main motor.

paedbo,
The Carbooon is yet another name for the Honeybee 2CP. I think thats the name they sell it by in Germany. I know because I have one, it's definately a HB2, but my Carbooon came with an 8t pinion. The HB2 also gets sold as the Twister in the UK and soon it will be sold here in the US by E-Flite as the Blade CP. Actually, if you look at E-Flite's upgrades they offer motors with 9t and 11t pinions. I've got a 10t laying around that I need to try.