I recently upgraded my carburator which included a small boost bottle and also upgraded my exhaust to F2 thruster! It's starts up much easier, idles better (i think I need to adjust it though) and takes of a bit faster! But still only max out at 25mph! Thought it should have added much more top end speed!??? Any thoughts! This all new to me! Only my 2nd build! And have just been hitting up amazon as I go for better parts!