Thanks Tom ! It looks still far from what Webra page is telling,
especially the rpm up to 16000 ??? With this propeller you
have got (calculated) power of about 2 bhp and 6kg thrust.
The company tells the engine has more than 3 bhp and if
calculate the propeller and rmp back that would give
for example on APC 14x6 thurst of 7.2kg at 12500 rm
which is about 2.9 bhp; that is about 30% more than
what you have got. Also I wander why Webra is advicing
propellers like 14x12 and 16x8, they seems too heavy
for this engine...