912 ULS with "hiccup" (mis fire)

Hi Coen,

"The vent line are routed "from factury" into the air filters"  This statement sounds to be contrary to Rotax instructions.

 The main function of the "vent lines"/tube is to keep the air pressure within the carburettor float bowl the same as the inlet air to the carburettor. By having the tube inside the air filter you may be lowering the air pressure in the float bowl. This is even more likely if the air filter is in poor condition or has become contaminated in use.