The Model Motors AXi 2208 range of brushless motors from Model Motors weigh only 45g and are suitable for small models and park flyers upto 500g in weight.
These motors are designed for mounting behind a firewall, however a radial mount set is available separately to allow the motor to be secured to the front of the firewall.
All AXi 22xx series motors should be used with "slow fly" type propellers for maximum efficiency.