Originally Posted by misfitsailor

I too use the VT .21, and love it. I have 10 or so 4-strokers, and this one is one of my very favorites. I had it on a cub first, but it has now logged many hours on a 40" Lazy Bee that I have set up for duration work. (I want to have the Lazy Bee with the longest flight ever) On this Bee, I have tried two different 2 stroke .10's, then a surpass .26, then a FS .20, but none could come close to the low fuel consumption of the HP .21! I am only up to 3 hrs 35min so far, but the development continues. My engine was one of the original Austrian ones, but all parts from Mecoa I have bought have fit and work nicely. I use a 10 inch prop for duration, but this engine likes about a 9x4 or 9x5 and 15% fuel, and will spin nicely and safely (over 13,000 rpm. no valves to float!). When flying with this engine, people have actually asked me what kind of batteries my plane was using! It is that quiet. I think this engine is overlooked and underrated. (details of duration plane upon request) P.S. Lazy Bees forever!