On the backing feature, the Yamaha does back very well (although the directionality can be difficult). The difference is the Yamaha prop. I have had the OMCs, McCulloughs and others and they are terrible with regard to power in reverse.

The reason for the limited power in reverse is that the exhaust feeds towards the back with a conventional prop, so that, in reverse, the prop cavitates because of the exhaust. The Yamaha prop (and it may be available with other motors) reverses the outlet for the exhaust, and the prop gets a tremendous bite. You might look into the Yamaha type prop for your motor. They might be available.