Hi Corky,
so, I read A lot of forums to answer these questions.
Since 2010 and the release of the v3 engine. Life expectancy is very good. Thousands of flights on engines and still going good. Aftermarket rings and reeds have also helped with lifespan.
Fuel burn was hard to find, approx 1 gallon per hour. ( my paramotor does 3/4 gph at full throttle.)
prop speeds seem to be best right about 6000 rpm for a 34x12 Mej prop. Anymore than that and it’s just slipping/ cavitating.
An electric starter can be made but is not widely used as no modeler in there right mind would put an electric starter on their plane.
Watch some YouTube videos of this engine on some giant scale planes. Sounds amazing.