I keep wondering about picking up this plane and stick my os 1.20 ax with pipe...
Power was litrally amazing.... the pipe added 900rps to the 17x6 apc prop...
It was unreal on a 69" yak... But the low end was lacking for 3d....

My thoughts..... If you want a great engine for this plane.... OS 1.20 ax will knock you socks off....
If you want more power...add a pipe....and you could do any routine....no problem..

I will wait till summer, as I had some issues with tunning with the pipe...
this may be fuel tank clunk related....
May add a pump and have not issues....at all with a muffled pipe...

Some say that the carb on the os 1.20 ax is too big and can make the settings sensitive...
If you use the stock muffler...it will work perfect....set and forget....
It is pipes that may be more of a issue...

Will report in spring...