These carbs are used in Rotax 912 as well as our Sauer S2500 Exactly 2 weeks ago I noticed I while on ground the take off with a trail of black smoke like a B52 but stopped at say 3300ft. Pilot reported lower than usual revs but improved.
Obviously a carb rich problem and after watching videos on rotax and Bing's I weighed the floats and 3 were 3gms while one was 5gms, the Max weight being 7gm for 2 floats. I borrowed a float from a 912 out of the air (found part elsewhere but less than half Bert floods price of $195 ea) Also noticed the arm on floats had been rubbing on side so closed up the rattle fit so it can no longer touch and adjusted the float arm to be about 5 deg from horizontal. The result is it has never ever run better. All CHTs on all four are within 6 deg C always and improved fuel economy. I am now at Alice Springs and fuel has improved from 13.3 lit per hour to 12.6 with a mix of 95 and Avgas but back to 98 at Alice. These carbs sr no were not part of a service bulletin re changing faulty floats. All I say is it is always worth checking the Bing float weights (Max 7gm for two) and remember the Bing's like slightly less fuel pressure than the CD150. Ian McPhee 0428847642 Box 657 Byron Bay NSW 2481