Bing Carburetor Flooding
in 912 / 914 Technical Questions
13 years ago
Both carbs on my Rotax 912ULS began to leak due to overfilling of the float bowls after only 95 Hobbs hours. The cause was permanent deformation of the Viton rubber tips on the needle valves. The deformation took the shape of the valve seat orifice and allowed the needle valves to seat almost 1/16 in. deeper in the valve housing. This allowed the fuel level to rise to the point that the bowls were overfilling. Bending the tabs on the float brackets didn't solve the problem. There was no damage to the valve seats in the carb body. New needle valves, float brackets, and gaskets solved my problem----temporarily---am I to expect to have to exercise the same cure after another 95 hours???? Lockwood Aviation Supply, Sebring, Fl. has some very convincing evidence (photos, etc.) that engine vibration can cause premature wear and failure of needle valves, float brackets, and other carb components.
