I just put together an Easysport 40 with an Evolution .455 engine. The engine originally came on my Alpha Trainer and has a Fly-Wheel on it; this added weight is supposed to make the engine run at a lower RPM. Why did I have to add 3 1/2 oz. of lead to the tail of the Easysport 40 to get the center of gravity correct? I changed the location of the battery to the rear compartment-seemed to help some. Is this too much weight?