I have a Su do koi (Morris hobbies) with a YS 45 on it. It hovers the plane at half throttle. I do not have a tuned pipe or tuned muffler on it, as it is not needed. I use the standard YS muffler. I think what stops people from using the YS 45 is its price. When a
$79-$110 dollar motor will hover it as well. The YS is a $180 dollar motor. I bought mine used for $100 and another one for $75. If you want to use a YS 45, try to find a used one. I used the YS 45 on a pizzaz first.