I am balancing the Extra and am tail heavy. If I move the battery all the way forward I still need to put 1.5 oz of weight - I attached (small screws) lead weight to the engine mount - basically the furthest point forward that I could attach weight to. I need to put the battery either on top of the the tank hatch, or inside on top of the tank which is a real squeeze. So I think I am going to put it on top of the tank. I figure I will just wrap it in 1/4 foam and then run ties around it and through some holes in the tank hatch - I will add more screws to hold the tank hatch down so it does break loose from the weight of the battery. My only concern is the battery is then open to fumes/moisture from the motor. I don't think this should be an issue because I have run these type of receiver batteries in Nitro RC cars and they survived. Do you see any issues with doing this?

Once I get this done I will actually be ready to go fly! I could have rushed to get it ready to take to the field this morning, but I was too tired from working too much. I had an interesting experience with my Aresti which has a YS 63 in it - it took off and then lost power - all I could do to get it back around and land. Turned out all the fuel had come out and was in the foam around the tank - the fuel line had cracked where it goes into the tank and with the high pressure system of the YS it pushed out 11oz of fuel in a hurry. I am going to replace all the lines and probably the tank itself. Also made a mental note to regularly replace the lines.