I wish we would have weighed them before we installed them, but at the time we did not have the intercooler and intake. I think I recall Jason saying they are slightly lighter than a 914? (4lbs maybe) of course that would be lost on the intercooler. My best guess is they are close to the same weight as a 914.
This is the first aircraft I have every flown with a rotax in it. I always thought the rotax where not that great. Now, I am no longer a rotax hater.
I am new to the Rotax so maybe others can chime in. Generally a stock 912 if its going to have an issue, it does right at first. If not they will run forever. So far I have been impressed and I am far from stock. They don't burn oil and run so much smoother than traditional engines. Good thing is I don't think the rotax drops jugs like a traditional aircraft engine sometimes does. They just put holes in the side of cases
That seems to only be happening to the big bores though. My point is they are very reliable engines. Stick and rudder would be a good resource as they run their training planes pretty hard.
I know your concerned about hand propping because of dead battery. Now days just carry a small jumper battery that weighs hardly anything. I understand if its not in the budget, but if it is possible the rotax would be one to take a hard look at because of its power to weight ratio. Just not sure what one would be best in your part of the country.
Looks like your doing your home-work so I am sure your aircraft is going to turn out great!