Hi.
I want to replace a YS engine 53 FZ which is installed in my GP Extra300s 40 ARF with a hot 2str.engine.
So,i want you to tell me disadvantages and advantages between the engines i have in mind!
Also,due to personal experience,please tell me which engine to you prefer and why?
Thank you.
Engine selection:

1) OS 65 LA.
2) OS 61 FX.
3) OS 46 AX.
4) Supertigre G61 ringed.
5) Supertigre G61 ABC.