Hi Mike, I am also flying a VW type 701. It is a 2100D Revmaster 75 hp direct drive.
I have about 110 hrs on it, it has not had any real problems to speak of except for the fact that I think it can be better than what it is.
It will rotate at 35 mph. Climb out at 45-50 mph is only 500 fpm, this is Pilot and full fuel, throw in a 150 lb passenger and it climbs at about 200fpm.
It is a good airplane with only the pilot, It does everything I need it to do. Cruise is around 75 mph at 3000 rpm and fuel burn has been about 5 gals per hour.
One thing Wayne touched on is the uneven fuel burn, mine is having the same problem which I hope to remedy soon. I have had a revflow carb on the bottom of the engine with a very long intake, which I am told causes poor atimization of the fuel,(The long intake that is) I am installing Bing 64 CV's like the Rotax uses, they will have very short intakes.
I hope this helps with your decision.
Remember the 701 was built around the Rotax.
Dwight

Mike,
I just got the engine and have to revise the wiring harness and get the whole thing installed before I can take to the skies.

Phil

I have had 2 701s and rotax 100hp is the way to go . Had 85 hp jabiru with the slats removed and vortex gens got the best rate of 600fpm . Rotax is off the ground in 3 seconds with no flaps/ no slats and 1200 fpm