There is still one more thing you'll need to do in order to get better idle, and that is you'll need to open the ventury openning to about 0.35 inch diameter the stock carb has to small of a ventury for the fuel demands, that is why it won't stay on while idling; just scrape the ventury hole with an xacto knife until you see that the diameter is a little bigger than the original hole,also gutt out the muffler and that would be your last modifications that you will need in order to have a smoother running, lighter engine, By the way the 25 FL engine likes to swing a 15x8 propeller but if you need a bigger diameter prop try an APC 16x4W prop and believe me you will have performance out of this baby!!!!