In another thread someone had identified the C-42 motor as the Rimfire 45-50-600. Here is a link to Electrifly's page:
http://www.electrifly.com/powersyste...ire-42-50.html
They discovered this when looking at the specs of the plane in the G3.5 simulator. I myself then went out with a ruler and measured the little sucker and found that its dimensions exactly matched those of the 45-50-600 rimfire. This motor has the potential to handle more power than the stock ESC and propellor can deliver. I have this plane and really like. It flies very smooth and slow so you have time to react. You will need a 4 cell 3200mah lipo or two 2 cell lipos. If you like nimh then two 7 cell nimh sticks 3000mah is all you can get in there without it being too heavy. There are two series battery connectors from the ESC. A three cell lipo isn't going to have enough power to comfortably fly this plane.

If the motor is a rebranded rimfire then there probably exists a nondisclosure agreement between Hobbico and Electrifly. I've read somewhere that Great Planes, Hobbico, Electrifly, and even TowerHobbies are all linked together somehow.

Since I've had my electristar I've made a few power enhancements to it. The cheapest of which is to replace the stock prop with a 12x6E or 13x6.5E APC prop. The 12x6E tends to give more thrust with less amp draw than the stock 11x7. (Not all prop brands are created equal.) The 13x6.5E gives even more thrust with slighly more amp draw. It just leaps off the ground. Since I read that the motor can handle a 5-cell lipo I just had to try it. I had already fried the stock ESC by getting it wet (was taking off on a pond dam and it landed in the water) and replaced it with a phoenix-80. The 5-cell gives it much greater ability to get out of tight situations, but remember though that the stock ESC can't hand 5-cells.