ORIGINAL: bigdanusa
The engine must be mounted inverted and some engines are harder to start or harder to keep running in that position. (I'm sure some others will disagree with me on that)
No disagreement here. I have the U Can Do 40 with a OS Max .65LA on her. I just installed a glow igniter to light the plug when the throttle is < 1/4 for the very reason you describe.
You really need to be careful not to treat this plane like a pattern ship or you will get severe flutter and probably control surface failure. Fly it slow however and this plane is a blast.