Hi!
Just forget building you own trainer using a gas engine! First of all using an engine like this is dangerous! -Count your fingers! It is supposed to be ten...you will be lucky if you still have them around after beginning your model flying career with a big gas engine...

Why invent the wheel twice???
There are numerous ready-built high winged trainers out there that are well contructed and fly well..why build an plane that probably will not even will fly well...
I know! We want to learn on our own...doing our own thing! Right!? Yea! But build your own plane when you have learnt to fly! When you have learnt on something that really fly!