I have experience with the 33 and other Evo engines.
They run fine with plenty of power.
If the engine has been broken in properly then you can run a 32:1 mix. If not then you will need to break it in with a 20:1 mix using regular old 2-cycle oil.
After break in I use synthetic oil (Klotz) mixed with av gas (100LL) . The av gas keeps the fuel lines and carb diaphragms from getting hard or you could use methanol-free pump gas too.

I would also change the plug just to be safe.

http://www.horizonhobby.com/pdf/EVOE33GX-Manual_EN.pdf