Good answers Bill. Gave me a bit of a chuckle.

Somehow you just need to loose about 2 lbs of weight or figure out how to put on a bigger engine. Powered gliders can do amazing things with lower power levels than "regular" models but 5 lbs (60 oz) for an 061 is just stacking the deck far too heavily against the poor engine.

Perhaps something like a 15 but with a cut down wider prop or even a 3 bladed one to get the blade area you need. A 15 generally works with a7 to 8 inch prop. No room even for those options? You would have to cut off the top of the engine pylon anyway to provide the new and larger mount. Build in an extra 1/2 to 3/4 inch of spacing.