Hi!
A 11x8 prop is way way too much pitch for a .46 twostroke engine. It's for a.61 two stroke!

When you fly a .45-.46 powered trainer airplane and most low winged sport airplanes an 11x5 or an 11x6 APC, RAM or Graupner cam-prop is what you should use. In a fast, small, Q-500 type airplane a 9x7,9x8 or 10x6, 10x7 APC could be used.

Regards!
Jan K
Sweden