ORIGINAL: FlyingGatsby
But I have two questions, the holes on the engine tabs, don't match up with the holes on the engine mount.
And I have a piece of balsa, with two holes drilled in it, and I don't see it used anywhere in the instruction manual.
Engine mounting is described on pages 15 & 16 of the manual. The picture is not very big so I can understand why it might be confusing.
The drilled ply part is the "pushrod support" mentioned in step 1-1 on page 18. The text describes adjusting its position and gluing it in. You can see it in the picture just above the text.